Another area where language variation plays a crucial role is in the study of
language change. It is the principal concern of historical linguisticsto investigate
how languages change over time, and until recently, historical linguists have studied
language change by relying exclusively on diachronic methods. These involve
analysing the structure of language from a succession of dates in the past and
highlighting those structural features (phonological, morphological or syntactic)
that appear to have changed over that period of time. For obvious reasons, if we are
considering a form of a language from many years ago, we do not have access to
native speakers of the language; as a consequence, historical linguists have had to
rely largely on manuscripts from the past as evidence of how languages may once