Language acquisition is used for the process where a language is acquired as a result of natural and largely random exposure to language, whereas the term language learning refers to the exposure structured through language teaching. Children acquire language from 18 months to puberty. The child's grammar is semantically based. Children reflect their competence through their performance. The aim of this study is to analyse their competence in both native and foreign language written texts they produced. Additionally, this study discuss if there is a significant difference between their performative competence level in Turkish and English. Therefore, 28 fourth graders were given a coloured picture representing a daily life of a family and they were asked to depict the picture in English and Turkish. Their written texts were discussed by Content Analysis and a corpus analysis. It has been found that how language acquirers write a text in Turkish and how well they reflect their foreign competence. It has been also shown that they were unable to use required foreign language competence because of lack of native language competence. Besides, they committed some spelling errors in foreign language.