The language of the primary school student presented an indicator of school maturity, he presented a necessary tool for learning activities and for socializing. Several authors have studied various aspects of language development in school-age children, but we hope that the lexical-semantic side has been insufficiently studied, while many learning difficulties can be caused by underdevelopment of vocabulary and comprehension of oral message or text. The article presents effective methods for examining the lexico-semantic side of language and describes the experimental results obtained, considering these results will guide primary school teachers to understand the learning difficulties present in some students and to implement improvement measures.