language spoken in addition to one's first language
A second language is a language that a person learns in addition to their first language. A second language may be learned in a formal or informal way, such as at school or in a family. A person may speak two or more second languages.
Adults do not learn languages the same way that children do. Learning a second language is difficult for adults, who rarely speak it as well as their native language because it is much easier for children to learn a second language.
Some children have native multilingualism and so speak several languages, such as by living in a foreign country or having a father speaking a different language from their mother.