Second Language

A second language or L2 is any language learned after the first language or "mother tongue". Some languages, often called auxiliary languages, are used primarily as second languages or lingua francas.

A person's first language is not necessarily their dominant language, the one they use most or are most comfortable with. For example, the Canadian census defines first language for its purposes as "the first language learned in childhood and still spoken", recognizing that for some, the earliest language may be lost, a process known as language attrition. This can happen when young children move, with or without their family (because of immigration or international adoption), to a new language environment.