First language

The monument for the Mother (Azerbaijani) tongue in Nakhchivan, Azerbaijan

A first language (also mother tongue, native language, arterial language, or L1) is the language a person first learns. A person's first language helps them understand words and concepts in the style of that first language.

Terminology

"First language" sometimes does not mean this, however.

Sometimes first language means the language a person speaks best (his second language is language he speaks less well than his first language, etc.).

Sometimes first language, second language and third language show how well one speaks a language, so a person can have more than one first language or second language.