Turkish Vowel Harmony and Suffixes, Explained Simply

Turkish vowel harmony is the rule that a suffix copies the vowel quality of the syllable just before it. Two-way suffixes choose between e and a (evler, kitaplar). Four-way suffixes choose between i, ı, ü and u (evim, kızım, gözüm, okulum). Because Turkish builds words by adding suffix after suffix, the rule runs through every word you say, so learning it early saves you thousands of small mistakes later.

The rules below follow the Turkish Language Association (TDK), which publishes the standard dictionary and spelling guide, and university grammar notes. Where a rule has exceptions, we list them.

The eight vowels and how harmony sorts them

Turkish has eight vowels (our guide to the Turkish alphabet and pronunciation covers how to say them), and harmony sorts them along two lines. The first is where the tongue sits: back vowels are a, ı, o, u and front vowels are e, i, ö, ü. The second is the lips: a, e, ı, i are unrounded and o, ö, u, ü are rounded.

Linguist Zeynep Korkmaz describes both rules in her notes on Turkish phonology in TDK's journal Türk Dili. The front/back rule, often called major vowel harmony (büyük ünlü uyumu), says that if the first syllable of a word has a back vowel, the following syllables do too (yakın, oyun), and the same holds for front vowels (ekmek, üzüm). The rounding rule, minor vowel harmony (küçük ünlü uyumu), says that after an unrounded vowel the next vowels stay unrounded, and after a rounded vowel you get either a/e or u/ü.

Plenty of native words break these rules inside the stem (anne, kardeş, elma), and so do most borrowed words (kitap, otobüs, televizyon). You don't need to memorise which stems are harmonic. For suffixes, only one vowel matters: the last vowel of the word you are attaching to.

Two-way harmony: e or a

Two-way suffixes have an e form and an a form. If the last vowel of the word is front (e, i, ö, ü), use e. If it's back (a, ı, o, u), use a. Grammar books often write these suffixes with a capital A, as in -lAr, to show the vowel can change.

• Plural -ler/-lar: evler (houses), kitaplar (books), gözler (eyes), okullar (schools)
• Locative -de/-da (in, at): evde, okulda
• Ablative -den/-dan (from): İzmir'den, Ankara'dan
• Dative -e/-a (to): eve, okula

Notice kitaplar. The stem kitap mixes i and a, but the suffix only looks at the last vowel, a, so the plural is -lar. The same logic gives otobüste (on the bus), because the last vowel of otobüs is ü.

Four-way harmony: i, ı, ü or u

Four-way suffixes have to match on both lines, front/back and rounded/unrounded. In practice you only need this table:

The four-way group is the bigger one. It covers the accusative (evi, kapıyı, okulu, gözü), the genitive (evin, okulun), possessives, the past tense -di (geldi, aldı, oldu, gördü), the question particle mi (güzel mi?, var mı?, doğru mu?, üzgün mü?) and common word-building suffixes like -li (with) and -siz (without): şekerli, tuzlu, sütsüz, akılsız.

How suffixes chain: ev-ler-im-de

Turkish words grow from left to right, and each new suffix harmonises with the vowel directly before it, which is often another suffix. For nouns the usual order is stem, then plural, then possessive, then case.

Take evlerimde, "in my houses":

1. ev (house). Last vowel e, front.
2. ev + ler. Front, so two-way -ler.
3. evler + im. Last vowel e, so four-way -im.
4. evlerim + de. Last vowel i, front, so -de.

Now the same chain on a back-vowel word, araba (car): araba + lar + ım + da gives arabalarımda, "in my cars". And on a rounded word: okul + lar + ımız + dan gives okullarımızdan, "from our schools". Each suffix looks one step back, never at the first syllable, so a chain can move between vowel types as it grows: göz + lük (glasses) takes ü from göz, then gözlük + ler takes e, giving gözlükler.

Verbs work the same way. gel + me + di + m gives gelmedim (I didn't come), and al + ma + dı + m gives almadım (I didn't take).

Two consonant rules ride along with harmony. After a voiceless consonant (ç, f, h, k, p, s, ş, t), suffixes that start with d change to t: kitapta, ofiste, gitti, baktı. And when a suffix starting with a vowel follows a word ending in a vowel, Turkish adds a buffer consonant, usually y: kapıyı, arabayla.

Common suffixes at a glance

The letter in brackets, such as the y in -(y)e, appears only when the word ends in a vowel. Two-way suffixes always contain e or a; four-way suffixes always contain i, ı, u or ü, so the dictionary form tells you the type.

Exceptions you will actually meet

Most of the system is regular, but a few suffixes and a group of loanwords don't follow it.

Suffixes that never change

Ankara University's course notes on Turkish spelling rules give two common cases. **The suffix -ken (while) keeps its e even after back vowels**: uyurken, bakarken. The suffix -ki (the one that is...) also stays fixed, as in sabahki, akşamki, yoldaki, onunki, with dünkü and bugünkü as rare exceptions.

A few others behave the same way:

• -yor, the present continuous, always keeps its o. The vowel in front of it still harmonises with the verb: geliyor, alıyor, okuyor, gülüyor.
• -leyin stays fixed: sabahleyin (in the morning), akşamleyin.
• -gil (someone's family or household) stays fixed: annemgil, teyzemgil.

The same notes point out that ile (with) joined to a word as a suffix does harmonise: komşuyla, taksiyle, kitapla, defterle.

Loanwords that take front suffixes

Some words borrowed from Arabic, French and English end in a back vowel but take front-vowel suffixes, usually because the final l or t is pronounced "soft". TDK's dictionary lists the suffix form with each entry, and it shows saat → saati (the hour), rol → rolü, alkol → alkolü, gol → golü, hâl → hâli and kalp → kalbi. You can check any word you're unsure about in TDK's Güncel Türkçe Sözlük: the ending printed after the headword, such as -ti or -lü, tells you which vowel the suffixes take.

There aren't many of these, and the frequent ones (saat, hâl, kalp, rol, gol) are worth learning as a set so they stop catching you out.

How to practise vowel harmony

Rules on paper don't help much until your ear starts doing the work. A few habits speed that up:

1. Learn each suffix as one item with variants, -lAr or -(I)m. One rule per suffix is easier to recall than two or four separate endings.
2. Say whole forms aloud. Evimde, okulumda, arabamda, gözümde is a better drill than writing -de in blanks.
3. Practise chains one step at a time. Pick a noun, add plural, then "my", then "in", and say each stage out loud.
4. Keep a short list of your exceptions (saati, geliyor, akşamki) and review it weekly.
5. Read and listen a lot. After a few weeks of steady input, evlarda starts to sound wrong before you can explain why.

Harmony mistakes don't usually block understanding, but they are among the first things a listener or an examiner notices. In C1 writing exams, a vowel-harmony slip in a long suffix chain tends to repeat across the whole text. If you're curious how harmony fits into the bigger timeline, our guide to how long it takes to learn Turkish covers that, and Turkish for living in Türkiye shows the everyday phrases where these suffixes appear most often. To see where you stand, the article on Turkish levels from A1 to C2 explains what each level expects.

Ceylan, our teacher, is a native Turkish speaker with an MA in Teaching Turkish and eight years of teaching from A1 to C2. She explains grammar like this in Turkish or English, one-to-one or in small groups, online.

Frequently asked questions

What is vowel harmony in Turkish?

It's the rule that suffixes change their vowel to match the last vowel of the word they attach to. Two-way suffixes alternate between e and a; four-way suffixes alternate between i, ı, ü and u.

How do I know if a suffix is two-way or four-way?

Look at the vowel in its dictionary form. Suffixes written with e/a (-ler, -de, -den, -mek) are two-way. Suffixes written with i (-im, -di, -li, mi) are four-way. Learning each new suffix with its type saves effort later.

Do loanwords follow vowel harmony?

Inside the word, usually not: kitap, otobüs and televizyon mix vowel types. Suffixes still follow the last vowel (kitaplar, otobüste), except for a small group such as saat → saati and rol → rolü, which TDK's dictionary marks.

Which suffixes don't follow vowel harmony?

The common ones are -ken (uyurken), -yor (geliyor), -ki (akşamki), -leyin (sabahleyin) and -gil (annemgil).

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