Vocabulary is an important sub-skill of language that is often found to be challenging to teach by language teachers. Constructed on intentional vocabulary learning through instruction, this study aims to provide insight into the understanding of teaching and learning vocabulary and explores if the vocabulary instruction through in-class vocabulary strategies developed by the researcher were helpful for Turkish 8th grade EFL (English as a Foreign Language) students English vocabulary retention in comparison to traditional vocabulary instruction. The data collected through the post-test and retention-test design were analyzed via SPSS 16.0. It was concluded that both in the short and medium term, there was a significant difference between the vocabulary retention scores of the students who were instructed with in-class vocabulary strategies (Experimental Group) and those who were given traditional instruction (Control Group) in favour of the Experimental Group.
Key words: intentional vocabulary learning, in-class vocabulary strategies, traditional instruction