Synchrony and
diachrony are two different and complementary viewpoints in
linguistic analysis:
- a diachronic approach considers the development and evolution of a language through history. The word is built on the Ancient Greek words δια "through" and χρόνος "time". Historical linguistics is typically a diachronic study.
- a synchronic approach considers a language without taking its history into account. The word is built on the Ancient Greek words συν "with" and χρόνος "time". Synchronic linguistics aims at describing language rules at a specific point of time, even though they may have been different at an earlier stage of the language. School grammar typically uses a synchronic (as well as prescriptive) approach.