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
... to the United States Census Bureau, the town has a total area of 4.4 km² (1.7 mi²). 3.3 km² (1.3 mi²) of it is land and 1.1 km² (0.4 ...