First Language
First language is not necessarily a single language.This is maybe the first language or first languages. one language. It's call mother tongue and they are native speaker
second language acquisition is the process which people learn a language that is not their native language or languages . Call that foreign language
two ways for learning foreign language
1. Learning grammar by study with teacher .
2. learning by natural
Age and language
Children under 7 years have ability to learn about language more than others .