Abstract-Lexis is one essential component of language and language development. Limited lexical knowledge can lead EFL learners to frustration and demotivation. To reach a higher level of development in the four basic communication skills, learners should have a basis of lexis that allows them to do so. One of the factors affecting the ongoing development of communicative competence is neglecting the systematic teaching of lexis. Teachers' lack of knowledge of the lexical field has contributed negatively to this current situation. To meet these needs, this article reviews concepts such as lexis/vocabulary, lexical competence and knowledge and size and depth of lexical knowledge. It discusses new perspectives that could help language teachers develop conceptual knowledge to handle lexical instructional practice.