One of the different shapes a single morpheme takes depending on its surroundings.
In precise terms
A phonologically or morphologically conditioned variant of a morpheme. Allomorphy is the morphological counterpart of allophony.
An example
evlerden / kitaplardan
from the houses / from the books
What is going on here
The Turkish ablative appears as '-den' after a front vowel and '-dan' after a back vowel. One morpheme, two shapes, selected automatically by vowel harmony. The meaning is identical.
Why this matters when you are learning a language
Recognising allomorphy turns apparent irregularity into rule. Turkish and Finnish endings look numerous until vowel harmony is understood, at which point most of the variation collapses.
Across languages
Vowel harmony drives allomorphy in Turkish, Finnish and Hungarian. English shows it in the plural, where '-s' is pronounced three different ways depending on the preceding sound.
Related terms
- MorphemeAdvanced — The smallest unit of a language that carries meaning or grammatical function.
- AllophoneAdvanced — One of the predictable pronunciations of a single phoneme, chosen by its environment.
- InflectionAdvanced — Changing a word's form to fit its grammar, without making it a new word.
Where to go next
- Language guides — See grammatical and lexical categories used in context.
- Terminology quiz — Test the terms on this page.