Introduction
Background of the study
Vocabulary is an essential component of foreign language learning, as highlighted by Wilkin (1972), who stated that without vocabulary, nothing can be conveyed (Thornbury, 2002) A large vocabulary not only facilitates communication but also significantly enhances the learning process, making it crucial for mastering a target language (Krashen, 1989) Despite the challenges of acquiring a substantial vocabulary in a foreign language, various strategies have been implemented to support L2 learners, including increasing their awareness of word families through morphological understanding.
Word families play a crucial role in assessing vocabulary size and understanding the lexical coverage required for learners to grasp various English discourses Nation (2006) suggests that to effectively comprehend authentic written texts, learners must acquire between 8,000 and 9,000 word families receptively.
Understanding spoken texts requires a significant vocabulary, with estimates suggesting that 6,000 to 7,000 word families are essential for basic comprehension For instance, to adequately understand television programs, learners need around 12,000 word families, while achieving 95.79% coverage of movies necessitates knowledge of approximately 14,000 word families, excluding proper nouns and marginal words Well-educated native English speakers typically know around 20,000 word families, with an average of 1,000 new word families added to their vocabulary each year during early development Therefore, a limited vocabulary can severely impede learners' comprehension in both academic settings and everyday communication with native speakers.
Expanding vocabulary through the acquisition of word derivatives can be challenging, primarily due to the necessity of understanding affixes Milton (2009) highlights that the complexities of affixes, including their meanings and multifunctional features, contribute to their difficulty in mastery Furthermore, many EFL learners often overlook the importance of affixes, focusing instead on memorizing word forms and meanings This neglect, coupled with inconsistencies in morphological rules, can lead to confusion, even among native speakers, as noted by Schmitt (2000) and Schmitt & Zimmerman.
Research indicates that the acquisition of derived forms of vocabulary is an incremental process that continues throughout students' school years (Tyler & Nagy, 1989; Nagy et al., 1993; Carlisle, 2000) Despite the significance of expanding vocabulary in English and the challenges learners face with derivational affixes, this crucial aspect of word knowledge is frequently overlooked in EFL classrooms and textbooks Gabig & Zaretsky (2013) noted that many educators remain unfamiliar with morphological aspects, highlighting a gap in teaching practices.
Research by Bryant (2006) and Wolter & Green (2013) indicates that morphological concepts, including affixes, are rarely addressed in classrooms Contemporary English textbooks used in Vietnamese high schools largely overlook morphological rules and internal word structures Many teachers in Vietnam assume that students only grasp the Vietnamese definitions, spelling, and pronunciation of words; however, students' reports reveal a more comprehensive understanding of word knowledge (Lưu, 2011) This gap between teachers' perceptions and students' actual word knowledge results in a neglect of teaching deeper aspects of vocabulary.
The primary motivation for this research stems from students' significant vocabulary shortages, particularly with morphologically complex words Despite several years of English study, many EFL learners struggle with these words, often forgetting them quickly, relying on bilingual dictionaries, or seeking translations in their native language for derivatives of familiar bases This challenge may be attributed to students' indifferent attitudes toward vocabulary acquisition (Lưu, 2011).
Students recognize the significance of vocabulary in their English studies, showing a moderate interest in expanding their lexicon However, they often hesitate to explore deeper aspects of word knowledge due to the challenges involved (Lưu, 2011) Additionally, the complexity of affixes poses a significant barrier to their vocabulary acquisition and growth through derivational affixes.
L2 learners often rely on their lexical memory to store morphologically complex words due to the complexities of affix functions and meanings, suggesting that morphological decomposition may not be utilized in their processing (Ullman, 2005) However, research indicates that L2 learners, regardless of their first language backgrounds, possess a conscious awareness of the internal structures of derived words, processing them similarly to native speakers (Koda, 2000; Brown et al., 2007) Consequently, enhancing morphological awareness among L2 learners has emerged as a significant area of focus (Mitchell & Brady, 2014) Morphological awareness, defined as the understanding of morphemic structures and word formation rules, has been shown to positively impact vocabulary acquisition in EFL learners (Bellomo, 2009; Kim, 2013; Wei, 2014; Harraqi, 2017), thereby providing a strong foundation for improved comprehension and vocabulary growth.
Most previous studies focused on students' progress in vocabulary learning through affixes as a supportive tool, rather than examining affixes as independent components Additionally, the importance of morphological instruction was often overlooked, with limited discussion on students' attitudes towards this method, which is crucial for its practical application This study aims to address these gaps in the literature by thoroughly investigating the implementation of morphological instruction specifically for teaching derivational affixes and their derivatives.
Context of the study
The study was carried out at the Center for Foreign Languages (CFL) at the University of Science (US) in Ho Chi Minh City, a prominent institution within Vietnam National University With nine faculties, US produces over 2,500 graduates and postgraduates annually, significantly contributing to the workforce in natural sciences Currently, the CFL serves 2,600 non-English-majored regular students across 82 classes and has been a pioneer in implementing innovative English teaching methods since the 2015 Decree from Vietnam National University aimed at improving graduates' English proficiency to meet labor market demands The researchers believe that this study will benefit both non-English-majored students and the CFL's development in enhancing English teaching quality Additionally, the researcher’s familiarity with the CFL's administration, curriculum, and learning environment facilitated the study's execution.
The study involved 60 non-English major students in their first semester of the 2018-2019 academic year at a university in the US, who were participating in a final English course These students exhibited lower motivation and less positive attitudes towards learning English compared to their English-major counterparts Additionally, their limited vocabulary significantly hindered their ability to express ideas effectively in both spoken and written communication.
Aims of the study
This study proposes the use of focus-on-morphological-rule instruction as an effective method for teaching derivational affixes to students It investigates the impact of this instructional approach on students' reception and production of morphological complex words and affixes over time The primary objectives include examining how this method influences the receptive knowledge of affixes and newly encountered derivatives among non-English-majored students in the U.S., as well as its effect on their productive knowledge of affixes.
This study investigates the impact of morphological-rule instruction on the derivation of word families among non-English-majored students in the US, assessing outcomes immediately after the instruction and again five weeks later Additionally, it explores students' attitudes towards the application of morphological rules in teaching derivational affixes.
Research questions
The aim of this study can be addressed via the following questions and sub-questions:
(1) To what extent does the application of morphological rules facilitate reception of the affixes and newly encountered derivatives of the US non-majored students at different levels over time?
The study investigates how effectively morphological rules aid US non-English-majored students in understanding affixes and new derivatives, both immediately and five weeks post-instruction.
(2) To what extent does the application of morphological rules facilitate the production of the affixes of the US non-English-majored students at different levels over time?
The study investigates how the application of morphological rules impacts the ability of non-English majors in the US to produce affixes at various proficiency levels, both immediately after instruction and five weeks later.
(3) To what extent does the application of morphological rules facilitate the number of derivatives within a word family produced by the US students at different levels over time?
The study investigates how the application of morphological rules impacts the production of derivatives within word families by US students at various proficiency levels, both immediately after instruction and five weeks later.
(4) What are the students’ attitudes towards the application of morphological rules in teaching derivational affixes?
Scope of the study
To support EFL students in expanding their vocabulary, this study focuses on morphological rules related to English derivation, which involves creating new words Specifically, 15 derivational affixes from Nation's (2001) affix list were selected as target rules for instruction and assessment These affixes were chosen for their relevance to the research objectives and their appropriateness for the learners' proficiency level, considering factors such as complexity, popularity, and productivity.
This study focused on receptive knowledge by examining students' ability to recognize and understand derivatives and derivational affixes within reading contexts, while productive knowledge was assessed through students' recall and application of these affixes in written contexts.
Significance of the study
This study aims to enhance previous research on morphological knowledge by focusing on its role in improving students' morphological awareness It seeks to provide additional empirical evidence supporting the benefits of teaching morphological rules, particularly in affix instruction and vocabulary development By addressing the existing gap in the application of morphology within English as a Foreign Language (EFL) contexts, especially in Vietnam, this research contributes valuable insights to the field.
An informal interview with lecturers and students at a US institution revealed a consensus among teachers that vocabulary learning should be an autonomous process for students They emphasized the importance of guiding students in using strategies such as context clues and dictionary lookup to acquire new vocabulary However, teachers noted that students often lacked understanding of the morphological aspects of words, and felt that teaching this knowledge might not be appropriate for their current level Consequently, students frequently demonstrated insufficient morphological knowledge and struggled to apply the limited understanding they had in vocabulary learning This finding aligns with Lưu's (2011) study, which highlighted teachers' negative perceptions regarding their students' vocabulary knowledge.
Teachers' and students' beliefs about vocabulary knowledge can hinder effective vocabulary instruction This thesis aims to enhance Vietnamese EFL teachers' understanding of how focusing on morphological rules, particularly derivational affixes and derivatives, can significantly improve students' vocabulary acquisition.
Outline of the thesis
This paper consists of five chapters: the introduction outlines the research rationale, context, aims, questions, scope, and significance; the second chapter offers a critical review of relevant literature across four key areas; the third chapter discusses the methodology, detailing the research method, pilot studies, participants, teaching materials, research instruments, and data collection and analysis procedures; the fourth chapter presents, analyzes, and explains the data; and the fifth chapter concludes the study with pedagogical implications, limitations, and recommendations for future research.
Literature review
Overviews of affixes and teaching morphological rules in EFL contexts
Before the 1970s, vocabulary teaching was often overshadowed by grammar instruction due to methods like the Direct Method and Audiolingualism, which resulted in limited vocabulary coverage in course materials (Thornbury, 2002; Boers & Lindstromberg, 2008) This lack of emphasis left learners with insufficient vocabulary, hindering their ability to retain and expand their word knowledge (Thornbury, 2002) However, the rise of communicative language teaching over the past four decades has shifted this perspective, leading to a greater recognition of vocabulary's critical role in second language acquisition Researchers, coursebook authors, and educators now view vocabulary as a fundamental element of language proficiency, essential for enhancing both receptive and productive language skills (Read, 2000; Thornbury, 2002; Boers & Lindstromberg, 2008; Schmitt, 2010).
Derivation is a key word formation process in English, involving the addition of affixes to create new words (Yule, 2010) Affixes, which are morphemes that appear before or after a base word, are not typically listed in dictionaries (Stageberg & Oaks, 2000; Yule, 2010) English features two main types of affixes: inflectional and derivational, with only derivational affixes serving a lexical function to form new words These affixes can be categorized into prefixes and suffixes based on their functions, such as nominal (-age, -al, -ance), verbal (-ate, -en, -ify), adjectival (-able, -ible, -ary), and adverbial (-ly, -wise) suffixes Additionally, they can be classified semantically, including negative prefixes (de-, dis-, un-) and locational prefixes (over-, under-, out-).
), personal-noun-forming suffixes (e.g –er, -ee, -ist), abstract-noun-forming suffixes (e.g –ation, -ment-, -sure), etc (Plag, 2003; Lieber, 2005; Lieber, 2009) According to
Research indicates that over half of English words are morphologically complex, with affixed forms outnumbering stems by four to one Additionally, a base word typically has an average of 1.57 transparent derivatives, suggesting that with knowledge of just 5,000 base words and affixes, learners can understand the meanings of approximately 7,800 words.
Derivational affixes are crucial for language development, significantly enhancing vocabulary size and knowledge among learners (Mochizuki & Aizawa, 2000; Bellomo, 2009; Nation, 2013) This section provides an overview of derivational affixes and the teaching of morphological rules, highlighting their nature, the importance of understanding these rules, and the necessity for focused instruction on morphological rules Additionally, it addresses how to measure affix competence and various methods for presenting morphological rules and derivational affixes to EFL learners.
2.1.1 Definitions and features of derivational affixes and morphological rules
Derivational affixes, as defined by Howard (1982), are prefixes or suffixes in English that create new words from existing ones by adding lexical functions (p.110) Arnold (1986) further emphasizes their role in providing bases with components of lexical and lexico-grammatical meanings, resulting in the formation of different words (p.87) These affixes can be categorized into two types: class-changing derivational affixes, which alter the word class of the attached words, and class-maintaining derivational affixes, which preserve the original word class.
Derivational affixes play a crucial role in forming various derivational paradigms, which consist of related words derived from the same base morpheme These new words are added to dictionaries through the application of morphological rules, which dictate the process of word formation As outlined by Plag (2003), effective word formation rules must include details regarding the affix's phonology, type, semantics, and applicable base morphemes.
10 since the rules did not focus on the phonological aspects of the affixes but rather mentioned their semantic and categorical information, the researcher considered them as
Derivational affixes encompass both lexical and grammatical meanings, highlighting their inherent lexical and grammatical features, including polysemy and generalization Furthermore, these affixes exhibit two crucial characteristics—productivity and categorical restrictions of attachment—derived from English affixes, as they are also classified as morphemes The following sections will delve deeper into these features.
The polysemy of the affix "-er" highlights its ability to convey multiple related meanings For instance, when attached to verbs like "write" and "drive," it forms agent nouns such as "writer" and "driver." Conversely, when added to words like "open" and "print," it generates instrumental nouns like "opener" and "printer." Despite the differences in noun types, all these terms share a common meaning: they represent "a person or a thing that carries out an action."
Polysemy in affixes occurs when a single affix can attach to various types of bases while carrying multiple meanings For example, the prefix "dis-" has three distinct meanings: "absence of," "opposite to," and "do the opposite of." This versatility allows it to form new words from verb bases, such as "discount" and "disappear." Additionally, it can create new terms from adjective and noun bases, including "disagreeable" and "discomfort," reflecting meanings of "lack of" and "not." In conclusion, the multifunctionality and polysemy of derivational affixes are key factors contributing to affixal polysemy.
Morphology, as defined by Fromkin et al (2011), is the study of the internal structure of words and the rules governing their formation, constituting a key aspect of an individual's grammatical knowledge of a language The authors emphasize that the internal structures of words are governed by specific rules, indicating that morphological rules play a crucial role in language understanding and usage.
Grammatical knowledge in English is shaped by rules that serve as generalizations or principles explaining linguistic data (Longman Dictionary of English Teaching and Applied Linguistics, 2010) These rules are applicable across various cases, leading to the generalization of morphological rules within the governing system of the English language.
Productivity is a defining characteristic of derivational affixes, yet its definition remains contentious within morphological studies Schultink (1961, as cited in Bauer, 2005) initially introduced the concept, but faced challenges distinguishing between intentional and unintentional coinage Aronoff (1976) proposed a definition based on the ratio of potential to actual words, but determining when a potential word becomes actual is problematic H Baayen and Lieber (1991) later introduced the "hapax-conditioned degree of productivity," measuring productivity as the number of unique words in a corpus divided by the total hapaxes Plag et al (1999) refined this into a formula for "productivity in the narrow sense," emphasizing that a higher count of hapax legomena indicates greater productivity of a morphological process This approach aligns with the views of Baayen and Renouf (1996), highlighting the significance of hapax legomena in assessing morphological productivity.
Although the formula suggested by Plag et al (1999) still encounters some limitations regarded the sampling of relevant tokens ad types, it can be seen that this formula
The current study advances previous definitions by highlighting the significance of hapax legomena and the varying degrees of productivity across different registers Consistent with the findings of Plag et al (1999) and H R Baayen & Renouf (1996), hapax legomena are identified as crucial for the productivity of specific morphological processes Consequently, the study posits that the capacity to create new words is a distinctive characteristic of derivational affixes, with all affixes chosen based on this criterion.
Constraints on derivational affixes and morphological rules
In English word formation, morphological rules apply only to a specific subset of words known as a pattern's domain, which is defined by constraints or restrictions These constraints significantly impact the use of derivational affixes, presenting challenges for English as a Foreign Language (EFL) learners According to Rainer (1988, as cited in Stekauer & Lieber, 2005), there are two primary types of constraints: processing constraints, which include token blocking and type blocking, and language-specific constraints, which encompass phonology, morphology, syntax, and semantics.
Token blocking refers to the phenomenon of the unacceptability of a morphologically complex word due to a synonymous word Take the word ―stealer‖ for instance
The term "stealer" is not considered morphologically complex due to the existence of the synonym "thief." Plag (2003) identifies three conditions for token blocking: synonymy, productivity, and frequency Synonymy allows an existing word to prevent the formation of a new one if they are completely synonymous, while productivity permits blocking when the blocked word is derived from a productive rule Additionally, the blocking word must be frequent enough to hinder the creation of a synonymous term Ultimately, these conditions indicate that word formation patterns must consist of potential words whose semantic, morphological, or phonological structures align with the language's rules and regularities (Plag, 2003, p.46).
The nature of morphological rules: word-based morphology and morpheme-
The study of morphological rules is essential for understanding the two explicit teaching methods utilized, as these rules are grounded in distinct theoretical frameworks Two key theories, the syntagmatic and paradigmatic approaches, serve as fundamental mechanisms in morphology The syntagmatic approach focuses on how linguistic elements combine sequentially to create larger units, emphasizing the internal structure of words, such as in the case of "decolonization," which consists of the affixes "de-," "-ize," and "-ation" combined with the root "colony." In contrast, the paradigmatic approach examines the systematic relationships between words that share common properties, viewing morphology as a collection of related elements For instance, "helpless" belongs to a group of words like "careless" and "speechless," all sharing the suffix "-less." These differing perspectives highlight the complexity of word formation and are categorized as "word-based morphology" for the paradigmatic approach and "morpheme-based morphology" for the syntagmatic approach, both of which are integral to the morphological analysis framework applied in the current study's lessons.
Morpheme-based morphology views morphology as the syntax of morphemes, governed by principles that dictate how morphemes combine to create words (Booji, 2005) This model illustrates that the process of forming words through morphological rules mirrors the structural organization found in syntax.
Syntactic rules in English combine words to form sentences, exemplified by the noun "buyer," which consists of the free morpheme "buy" and the bound morpheme "-er." In this case, "buy" is categorized as a verb (V), while "-er" is an affixal morpheme that forms nouns (N) The creation of the complex word "buyer" follows the principle of concatenation, which is the linear combination of elements Its morphological structure can be represented as [[buy]V[er] N-aff] N Additionally, polymorphemic words, such as "tranquilizer," are formed through the concatenation of morphemes, including those from other polymorphemic words This word can be analyzed as [[[tranquil] A [ize] Vaff] V [er] Naff] N Morpheme-based morphology emphasizes the principles guiding language users in the correct combination of free and bound morphemes to create well-formed words.
Morpheme-based morphology treats morphemes as lexical items that share key characteristics with words, including their own meanings, phonological specifications, and syntactic category designations This understanding highlights the significance of morphemes in linguistic structure, emphasizing their properties akin to those of words.
The theory of word-based morphology, introduced by Aronoff in 1976, identifies various word formation processes, including acronyms and affixation, as Word-Formation Rules (WFR) These rules are grounded in a central hypothesis that guides the understanding of how words are formed.
All standard word-formation processes rely on existing words, where a new term is created by applying a consistent rule to an established word Both the newly formed word and the original word belong to significant lexical categories.
Word-based morphology posits that morphemes do not exist independently or as separate entries in the lexicon Instead, it elucidates the connections between morphologically related words by formalizing their shared features within a morphological schema This perspective suggests that new words emerge through the systematic extension of established form-meaning relationships.
―not X‖ words to new cases For instance, the relationship between the set of bases including
―able‖, ―clear‖, ―common‖, ―friendly‖, and ―pleasant‖ and the set of derivatives
―unable‖, ―unclear‖, ―uncommon‖, ―unfriendly‖, ―unpleasant‖ can be described as the following schema:
The morphological schema illustrates a relationship between the base adjective "A," represented orthographically as /X/ and phonetically as /X/, which conveys the meaning "X." This base adjective connects to other adjectives that are formed by adding the prefix "un," resulting in the orthographic form /unX/ and the phonological form /ʌnX/ These "unX" adjectives carry the meaning "not X." The non-directional relationship indicated by the double arrow signifies that the derivation can occur in both directions.
Morpheme-based and word-based morphology both offer valuable insights into word formation and morphological analysis, each with its own advantages The current study's morphological rules are based on the word-based model, which poses challenges for EFL learners, particularly non-English majors who may struggle with the concept of morphology This approach suggests that learners must first acquire a substantial vocabulary before they can effectively recognize and categorize related words to create new ones Unfortunately, this requirement can hinder non-English majors, who often lack the necessary vocabulary However, these learners do possess some foundational knowledge of common morphemes from their previous exposure to English in secondary and high school, which can aid their understanding of morphological rules.
Explicit teaching of affixes significantly enhances vocabulary acquisition and morphological knowledge, as supported by various studies (Nagy & Anderson, 1984; Anglin et al., 1993; Schmitt & Meara, 1997; Sudana, 2006, as cited in Kim, 2013) This study integrates both word-based and morpheme-based morphology, first teaching the meaning, form, and use of morphemes as independent lexical entries Following this, morphological rules are introduced to demonstrate how morphemes combine to form new words, clearly specifying the grammatical categories and meanings involved This dual approach aims to provide learners with a comprehensive understanding of morphology and enhance the effectiveness of the teaching method within the study's limited timeframe The experimental group engages in a two-step learning process, while the control group receives a more traditional instruction method, focusing on memorization of word families without explicit morpheme teaching or morphological rules In the control group, the changes from base words to derived forms are emphasized, with meanings translated into Vietnamese, mirroring high school practices The comparison of these two teaching models may reveal new strategies to improve EFL learners' understanding of derivational affixes and overall vocabulary development.
The explicit teaching of derivational affixes and morphological rules
2.3.1 Theoretical support for the explicit teaching of derivational affixes and morphological rules
Research indicates that morphological instruction in EFL classrooms is underutilized, yet studies show that explicit teaching of morphological knowledge significantly enhances vocabulary acquisition and morphological awareness among EFL learners (Nakayama, 2008; Xinjie, 2011; Lu, 2013; Wei, 2014; Fotokian & Rahmatipasand, 2015; Amirjalili et al., 2018) The positive outcomes of these studies are likely supported by the noticing hypothesis and Levels-of-Processing Theory.
Noticing hypothesis was first mentioned by Schmidt (1990) According to Schmidt,
Noticing is a crucial element in second language acquisition, as it involves conscious attention to input features, which is vital for both incidental and intentional learning Schmidt proposed a fourfold framework to clarify the concept of consciousness in language learning, encompassing intentionality, attention, awareness, and control.
In applied linguistics, "intentionality" refers to learners actively increasing their exposure to the target language through voluntary practice outside the classroom "Attention" is defined as the subjective awareness of focal attention, which is crucial in second language acquisition Researchers emphasize that learning cannot occur without attention to the material being learned, highlighting the significance of conscious engagement in the learning process.
Consciousness is defined as awareness, which encompasses both implicit and explicit learning Klein (1986, as cited in Schmidt, 1994) highlights that awareness involves the process of "noticing the gap," where students compare their own outputs with those of others, enabling them to learn from their mistakes until the discrepancies are resolved This underscores the critical role of awareness in the gap noticing process Additionally, the concept of consciousness also pertains to "control," further emphasizing its significance in the learning experience.
―control‖ in language learning can be seen as the problem of fluency ―Consciousness‖ as
―control‖ is expressed in the process of learners from the stage of trying to utilize mental
In the context of language learning, the four standardizations of "consciousness" highlight the crucial role that awareness plays in the process Students are encouraged to focus more intently on their communication, leading to a heightened level of automaticity in grammatical usage This approach emphasizes the importance of understanding and internalizing paradigms taught in class to effectively convey ideas.
The noticing hypothesis suggests that language learning is enhanced when learners focus on specific linguistic features they need to acquire Unlike first language (L1) acquisition, second language (L2) acquisition requires conscious attention to these elements for effective learning (Schmidt).
L2 learners must intentionally focus on language learning, particularly on linguistic units like English derivational affixes Explicit morphological instruction enhances their awareness of these forms, initiating a deliberate learning process This approach enables students to identify discrepancies between their language output and the input they receive, fostering comprehension and integration of new knowledge As they bridge the gap between existing and new information, learners can effectively memorize and retain affixes, ultimately transforming their receptive knowledge into productive skills for creating new words This aligns with Hulstijn's (2005) assertion that explicit learning of declarative knowledge and attention to input features significantly aids the development of procedural knowledge in students.
Another theory of central relevance to the effectiveness of explicit instruction in teaching derivational affixes is Levels-of-Processing theory first proposed by Craik & Lockhart
(1972) According to this theory, the level at which the information is mentally processed is directly proportional to the possibility of them to be committed to long-term memory
Focus-on-morphological-rule instruction enhances learners' understanding of derivational affixes by thoroughly explaining their meaning, form, and usage, which may require additional time and effort to process the information Students are encouraged to activate their prior knowledge of derivational affixes to infer the meanings of derived words in context and to identify words with similar internal structures for analysis.
Facilitating tasks that encourage students to analyze the structure of derived words and combine bases with suitable affixes enables a deeper processing of language input This approach goes beyond rote memorization of word families, as it emphasizes understanding the roles of affixes and the meanings of derived words Ultimately, engaging with derivational affixes and morphological rules through multi-level processing enhances retention and comprehension.
2.3.2 Previous research on explicit instruction on morphological knowledge
In Vietnam, the use of morphological rules in vocabulary teaching, particularly regarding word families, has received limited attention Despite this, researchers like Trần (2008) and Đinh (2008) have explored the role of derivational affixes in enhancing vocabulary learning and reading comprehension, particularly for TOEIC test preparation However, these studies treat derivational affixes merely as tools for improving language skills rather than as essential components that require explicit instruction Additionally, the research has not sufficiently examined derivational affixes in the context of vocabulary development, a gap that remains in the Vietnamese educational landscape.
Current research on the benefits of morphological rules in vocabulary acquisition is limited, particularly in Vietnam However, various studies conducted internationally have investigated the impact of explicit instruction in morphological knowledge on enhancing vocabulary acquisition and development.
Research has extensively explored the impact of explicit morphological instruction on vocabulary acquisition among EFL learners A study by Nakayama (2008) focused on the effects of systematic vocabulary teaching using prefixes with 69 Japanese university students from four intact classes Participants were divided into control and experimental groups, further categorized into two levels based on their TOEIC scores Both groups received identical materials and instruction, with the experimental group benefiting from additional mini-lessons on prefixes.
In a study involving 34 target prefixes, students in the experimental group engaged in a structured learning process during the first week, which included guessing the meanings of words, verifying answers through a PowerPoint presentation, and practicing pronunciation Both groups received presentations of 50 target words with their Japanese meanings, but the experimental group had the target prefixes highlighted in a different color After memorization, participants took an immediate test featuring 50 sentences with underlined target words to assess retention A follow-up test was conducted a week later to evaluate long-term retention Results indicated that the experimental group outperformed the control group in the immediate post-test; however, their performance in the delayed post-test did not show significant improvement compared to the control group or their own immediate results This suggests that while systematic teaching of English prefixes enhances short-term retention, it does not ensure long-term retention for students across varying proficiency levels.
The study by Nakayama (2008) has notable limitations, primarily due to the brief exposure time of the experimental group to the target prefixes during a single lesson, making it challenging to draw reliable conclusions about the impact on vocabulary learning Additionally, the absence of a pre-test to assess students' prior knowledge of the target prefixes complicates the evaluation of whether the observed progress stemmed from the treatment or existing knowledge Furthermore, Nakayama acknowledged that the test format was a weakness, as varying levels of contextual clues in the sentences could lead students to infer meanings without a solid understanding of the prefixes, ultimately affecting the accuracy and reliability of the results.
In addition to vocabulary learning process, aspects of new words such as meaning, part of speech and form can also be facilitated by morphological rules Xinjie (2011)
A study examined how word-formation rules can aid vocabulary acquisition among ten first-year teacher education students in Sweden Researchers selected ten affixes and twenty advanced English words that shared these affixes for the study After a pre-test, students attended a lecture on the affixes and word-part strategies, followed by two vocabulary tests Results showed high accuracy rates of 69.5% for Test A and 67.5% for Test B, indicating that the word-part strategy effectively facilitated understanding of new words The findings revealed that students with larger vocabulary sizes utilized the strategy more effectively, acquiring more words Additionally, students expressed a need for more practice with the strategy Consistent with previous studies, the research highlighted the positive impact of explicit affix teaching on vocabulary understanding, particularly when students were familiar with word roots The study also identified that difficulties arose from a lack of root knowledge, yet the word-part strategy assisted in deciphering word meanings and classes Overall, explicit instruction in affixes significantly enhanced students' vocabulary acquisition, provided they had sufficient practice time.
36 experiment time length In addition, the lack of a control group and a sufficient sample size are also the limiations of this research
Summary
Chapter 2 provides a theoretical background to this study, including the definition and features of derivational affixes and morphological rules, the teaching of derivational affixes, the nature of morphological rules and theoretical support for the explicit teaching of morphological rules to EFL learners Some gaps remaining in the existing literature on the productive master of affix knowledge and how morphological rules can be used as an effective method to enlarge the students’ vocabulary size are also identified in this study This chapter also indicated how the findings of this study contributed to the body of knowledge
Morpheme-based morphology (Selkirk, 1982; Booji, 2005)
Affix knowledge Vocabulary size Vocabulary knowledge Attitudes
-Increased number of derivatives in word families