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
... average household size is 2.41 and the average family size is 2.88. In the town the population is spread out with 20.6% under the age of 18, 5.0% from 18 to 24, 26.8% from ...