In this chapter linguistic variations are examined by focusing on the different dimensions that influence them, including the communicative situation, the interlocutor, and the linguistic repertoire. Variations are discussed within the new theoretical perspective that considers language as a social action and social factors as part of language functioning. The diachronic and synchronic lexical change is explored and the development of a linguistic norm for sign language together with a consideration of the role of sociolinguistic factors in the shaping of metalinguistic reflection are discussed. Finally, euphemisms and taboo in LIS are explored as an area that shows how usage interacts with pragmatic and social norms.