The importance of vocabulary, its types, selection criteria, size and depth, and teaching principles were found unclear. The present article seeks to respond to such challenge. To achieve the mentioned goals, we did a systematic review to previously related studies and theories. The results showed that the vocabulary was found to be more…

This paper is concerned with research in measuring receptive and productive vocabulary knowledge in second language (L2) learning, including English as a second language (ESL) learning and English as a foreign language (EFL) learning. The paper will begin with a brief introduction to the role of vocabulary in language learning, and then an…