The Effects of Morphological Awareness on L2 Vocabulary Knowledge of Thai EFL Young Learners

Abstract

Morphological awareness (MA) is the ability to manipulate words, recognize the association between different morphological forms of a word, and produce new words. Morphological instruction mediates the acquisition of new words and is crucial for developing morphological awareness and vocabulary knowledge. Currently, the receptive-productive continuum of MA remains unclear, especially in an EFL context. Thus, this quasi-experimental research examined the effects of MA instruction on acquiring morphologically complex words and its impact on vocabulary knowledge among young Thai EFL learners. This study also examined the relative contributions of MA aspects to vocabulary acquisition and development both receptively and productively. The five-point Likert scale questionnaire was also employed to explore the experimental participants’ perceptions in implementing morphological awareness instruction on vocabulary learning. The participants were Thai native speakers and had not studied in an English-speaking country. At the time of data collection, they had seven to nine years of experience learning English, which has been taught as a compulsory school subject for at least seven years. Participants in the experimental group (n = 110) were provided explicit instruction on MA based on Bauer and Nation’s (1993) word families, while participants in the control group (n = 111) did not receive this instruction. Six receptive and productive MA measures and four vocabulary knowledge measures were administered to 221 EFL young learners. Descriptive and inferential statistics were used to analyze the quantitative data.

The current results show that young Thai EFL participants’ morphological knowledge occurs on a developmental continuum. Indeed, the recognition of individual affixes is acquired before production. Specifically, the participants in the experimental group showed improved performance in both receptive and productive MA. This suggests that the explicit instruction of morphologies may benefit English learners in understanding words and ease vocabulary acquisition. It was also shown that morphological instruction in a regular English language classroom in an EFL context is a valuable learning tool. Indeed, explicit instructions of affixes in English facilitated the acquisition of word knowledge (e.g., meaning and linguistics). Furthermore, it seems that young Thai EFL participants’ morphological awareness increases in line with their vocabulary level and follows a predictable progression, indicating which prefixes and suffixes should be introduced first. Learners’ perceptions of morphological awareness instruction showed that the participants strongly considered the influence of morphological awareness instruction in their classes. Moreover, students agreed that the morphological awareness instruction assisted them in learning new words and expanding their vocabulary knowledge. In conclusion, MA knowledge is an essential, sublexical component of word knowledge that facilitates vocabulary learning, and explicit MA instruction can stimulate the acquisition of word knowledge. In this context, longitudinal studies would be precious. Studying English affixes in various situations and levels of English language skills would also be especially beneficial. Additional affix acquisition studies (e.g., one by one, grouping) would significantly contribute to the theoretical and practical frameworks for vocabulary development.

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