Language transfer (also known as L1 interference, linguistic interference, and crosslinguistic influence) refers to speakers or writers applying knowledge from one language to another language. It is the transfer of linguistic features between languages in the speech repertoire of a bilingual or multilingual individual, whether from first to second, second to first or many other relationships. It is most commonly discussed in the context of English language learning and teaching, but it can occur in any situation when someone does not have a native-level command of a language, as when translating into a second language.