ABSTRACT
Language change – variation over time – has its origins in spatial and social variation. The source of change over time is always variation. Sociolinguists try to identify the particular social factors which favour the spread of specific linguistic changes, and they try to explain how the factors influence the spread of the change. Comparing the speech of people from different age groups can be a useful clue, then, to language change. The apparent-time method of studying language change is a useful short-cut for sociolinguists who generally cannot afford to wait around for twenty years to see what happens in real time. People normally use more vernacular forms while they are young, and tend to use more standard forms as they get older and respond to the pressure of society's expectations. A change which introduces a vernacular variant into a community will infiltrate people's more casual speech styles first.
