Language 1 L1 Terms are used to indicate that a person has acquired the language in infancy and early childhood & generally within the family. Level of Proficiency in language. Language 2 L2 non-native language, 2nd language) implies the prior availability to the individual of an L1, some form of bilingualism. May indicate a lower level of proficiency. Phonology producing the basic sound units of language Morphology word formation in a language including inflection, derivation and compo...