Universal Grammar involves 3 factors: 1. GENETIC ENDOWMENT: Sets limits on the attainable languages, thereby making language acquisition possible. (Universal grammar in the first theoretical sense). 2. EXTERNAL DATA: Converted to the experience that selects one or another language within a narrow range. (Linguistic data to which the child is exposed). 3. PRINCIPLES NOT SPECIFIC TO FL: FL is the faculty of language, whatever properties of the brain cause it to learn language. (Hariyanto, 2011)