The effects of Explicit Teaching of Some Derivational suffixes to L2 Learners of Persian

Teaching L2 vocabulary through different techniques, plays an important role in the enhancement of vocabulary knowledge. This study investigated teaching derivatives through explicit and incidental approaches. Explicit approach, has specifically focused on word part strategy and the roles and meanings of suffixes. In incidental approach, some texts included derivatives, were taught to L2 learners. Two hypothesis were considered: 1. teaching affixes explicitly would help guess the meaning and part of speech of words and this kind of instruction affects learners’ comprehension positively. 2. More exposure to derivatives would influence on understanding unfamiliar words and vocabulary knowledge effectively. After a pilot experiment, 40 Persian learners of Dehkhoda institute in intermediate 1 level were selected and examined for this investigation. They were divided into two groups, the controls and the experimentals . During the instruction, those suffixes were selected that were more frequent in core vocabulary. Suffixes such as /-gar/ which makes job names (in /bɑzigar/ that means actor) or suffixes which make a new grammatical category such as noun making /-eʃ/ (in /dɑneʃ/ that means knowledge), were selected for teaching and testing. 4 texts, included unfamiliar derivatives, were taught to control group. There were two reading comprehension questions after each text. In contrast, the meaning and usage of affixes were instructed to experimental group and then some exercises were given to them. The subjects participated in one test which was administered twice as pretest and posttest before and after the treatment. The result of data analysis showed that the experimental group who received explicit teaching of suffixes and word formation, improved significantly in comparison with the control group who received some texts. Therefore, the first hypothesis was confirmed. Furthermore, it was proved in another analysis that the posttest result of two groups outperformed the pretest significantly. Hence, the second hypothesis was proved out. However, incidental teaching of derivatives can affect vocabulary knowledge, the result of explicit teaching is still more meaningful.