Abstract: The object of this research is to describe and comprehensively understand cognition in second language acquisition in children aged 1; 5 years: a formal approach to the type of Krashen monitor theory. The method in this study uses a qualitative approach. Qualitative because based on taking a historical data in the form of observation and recording using electronic media as a recorder of speech forms.Data is collected through data collection by recording and then recording one word and two words from the child's speech then describing it syntactically the words that the child uttered. The method used is observation and conversation by asking a few questions. The object in this study was a child named Raffasya Wirayudha who was 1; 5...