Turkish vowels come in two harmony groups. The last vowel in a word controls which vowel you use in many suffixes.

The Two Groups

Group Vowels Feel
Back a ı o u said toward the back of the mouth
Front e i ö ü said toward the front of the mouth

Note: Turkish has two “i” sounds: i (dotted) and ı (dotless). They belong to different groups.

VOWEL SOUND TYPE
A BACK
I BACK
O BACK
U BACK
E FRONT
İ FRONT
Ö FRONT
Ü FRONT

The Simple Rule

Find the last vowel in the word:

  • If it is a ı o u, pick the back version of the suffix.
  • If it is e i ö ü, pick the front version of the suffix.

That is the core of vowel harmony.

Plural: -lar / -ler

Plural uses -lar for back vowels and -ler for front vowels.

Word Last vowel Plural
kitap (book) a kitaplar
okul (school) u okullar
araba (car) a arabalar
ev (house) e evler
şehir (city) i şehirler
göl (lake) ö göller

Other Common Suffixes

Many suffixes have a two-way version (a/e) or a four-way version (ı/i/u/ü).

Two-way examples (a/e)

  • -da / -de (in/at): evde, okulda
  • -dan / -den (from): evden, okuldan

Four-way examples (ı/i/u/ü)

  • -ım / -im / -um / -üm (my): kitapım, evim, okulum, gölüm

If the suffix has four vowel options, it still depends on the last vowel — just with a finer match.


If you can spot the last vowel quickly, most suffixes fall into place.


Photo by Roman Petrov on Unsplash