To be able to use the target language sentence structure efficiently, a speaker needs to learn and have a very large number of words (Nation, 2013). Research shows that understanding the meaning of a word is not sufficient, rather, it involves more than just its meaning; such as spelling, and grammatical behavior (Pigada & Schmitt, 2006). Vocabulary acquisition requires effective methods. One of the methods of learning vocabulary is learning the process of word formation in the target language. This research aims at investigating and exploring one of the productive word-formation processes in the English language which is conversion or zero-derivation in which the grammatical category of a word is changed without adding any affixes. For instance, every day, I walk(V) to the park near my house, or, every day, I take a walk(N) with my dog. The results will have several pedagogical implications for researchers, teachers, and learners. Based on the presented data in the current study, it can be concluded that zero-morph can be considered one of the productive word-formation processes, and pedagogical implications are discussed in the discussion section.

Keywords: Word-formation, conversion, Kurdish EFL learners, vocabulary acquisition