The effects of exposure frequency and grammatical classes of words on receptive and productive vocabulary knowledge of EFL learners

Vocabulary learning is an important part of learning a language. Therefore, in foreign language classes important amount of class time is allocated to vocabulary teaching and it is aimed to improve learners? productive and receptive vocabulary knowledge. However, it is observed that while some words are productively known, some of them are receptively known and some others are not known at all by the learners. The reasons of this have been the focus of different studies.The present study aims at finding out the relationship between the exposure frequency and grammatical class of words and the level of knowing words. With regard to this, the first aim of the study was to investigate whether there was a relationship between exposure frequency and levels of knowing words. The second aim of the study was to find out whether there was a relationship between the level of knowing words and the grammatical class of words.To achive these aims, this study was conducted with 20 pre-intermediate level students studying at Nigde University Preparatory program. For gathering data, a ?Vocabulary Knowledge Scale? which included 63 words was used as an instrument. These 63 words consisted of 21 words chosen from each of 3 exposure frequency band. Each set of 21 words were made up of 7 nouns, 7 verbs and 7 adjectives.The data were analyzed descriptively and statistically. The findings indicated that there was a relationship between exposure frequency and levels of knowing a word. It was found out that the students did not know majority of the words they were exposed to up to 5 times and they knew productively majority of the words they were exposed to more than 11 times. It was also found out that the percentage of the words known receptively were close in each of three exposure frequency bands.The findings indicated a significant relationship between grammatical classes of words and levels of knowing them. Adjectives were found to be known mostly productively; whereas, verbs were found to be mostly known receptively.