Example
The English plural morpheme for nouns has three allomorphs:
(notation in SAMPA)
from: Iggy Roca and Wyn Johnson, a course in phonology, Blackwell, 1999; p. 621
... doesn't have to deal with their wrongs of the past, they don't call themselves quacks, they can change their name to whatever is trendy at the time, e.g. herbalist. ...