(1) The temporal axis. Language is permanently changing, which perhaps
helps explain why each generation complains that the following generation
no longer speaks the language properly. However, change can have different
consequences for different languages. English has, for example,
relatively recently gained the words streaker and punk and is in the process
of losing the pronouns thee and thou. These changes will, however, have
little effect on the English language community. English, as result of these
changes, is in no way endangered. It is a different case, however, for a
linguistic minority, where changes may be interpreted as symptoms of
language decline. Haugen (1980) has coined the concept of the cycle of
language shift whereby a monolingual community gradually introduces L2,
the dominant language. For a period of time there is a lot of interference in
L2 from LI. After a while there comes a diglossic situation. Following this
the interference stems from the dominant language L2 and is found in the
minority language Ll. Finally monolingualism is reintroduced following the
extinction of L 1.
In the declining East Sutherland Scots Gaelic dialect showing interference
from the dominant L2 English, Dorian (1977, p. 23)