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
... Karl Friedrich Rosenkranz Johann Karl Friedrich Rosenkranz (April 23, 1805 - July 14, 1879), German philosopher, was born at Magdeburg. He read philosophy at Berlin, ...