Islam

: The objective of this research is to describe the language acquisition of children on the aspects of vocabulary mastery and description explained the children language acquisition itself in their daily life. The subjects of this study are children aged 5-6 years at TK Islam Terpadu Bintang Belia.The type of this research is descriptive qualitative. Data collection methods used in this study is the method of observation. The techniques used in this research is the technique of collecting data with basic techniques of tapping, uninvolved conversation observation technique, and advanced techniques of record. Researchers also use interview techniques to obtain data of vocabulary mastery of children. The population in this study are all children aged 5-6 years in TK Islam Terpadu Bintang Belia. The sampling technique used in this research is saturation sampling. The results show that children aged 5-6 years have mastered various categories of words. 1) The categories of words that are most dominated by children are nouns, verbs, adjectives, adverbs, numerals, pronouns and the word task. Children tend to overwhelm the vocabulary that exists in their daily lives. 2) The use of vocabulary controlled by children in everyday speech consists of representative, directive, expressive and commissive.