Turkish suffixes do not have a single spelling — the plural is sometimes -ler and sometimes -lar, the locative is -de, -da, -te or -ta, and so on. Memorizing each of those surface forms separately is the slow, error-prone way to learn Turkish. This page teaches the shortcut that linguists and good textbooks use: writing each suffix once, in capital-letter notation, and generating the right form on the fly. Master this notation and a single line, -lAr, replaces a list of variants you would otherwise have to drill.
What the capital letters mean
A capital letter inside a suffix is not a letter you write. It is a placeholder — an "archiphoneme" — that stands for a whole set of vowels or consonants, and it tells you to pick the right member of that set by the rules of vowel harmony and consonant assimilation. Lowercase letters in a formula are fixed; capital letters change.
| Symbol | Stands for | Chosen by | Surfaces as |
|---|---|---|---|
| A | { e, a } | frontness of last stem vowel | e (front) / a (back) |
| I | { i, ı, u, ü } | frontness and rounding of last stem vowel | i / ı / u / ü |
| D | { d, t } | voicing of the sound before it | d (after voiced) / t (after voiceless) |
| C | { c, ç } | voicing of the sound before it | c (after voiced) / ç (after voiceless) |
| (y) | buffer consonant | appears only after a vowel | y or nothing |
So A is the two-way (low) vowel: it only ever comes out as e or a, never as a high vowel. I is the four-way (high) vowel, the trickier one, because it also has to match rounding. We will take them one at a time.
A = e / a (the two-way vowel)
Whenever you see capital A in a formula, ask one question: is the last vowel of the stem front or back? Front vowels (e, i, ö, ü) pull the suffix to e; back vowels (a, ı, o, u) pull it to a. Rounding is irrelevant here — A has no rounded option to choose.
The plural suffix is written -lAr. That single formula generates both surface forms:
Çocuklar bahçede top oynuyor.
The kids are playing ball in the garden.
Evler çok pahalı olmuş, hiçbirini alamadık.
The houses turned out very expensive; we couldn't buy any of them.
In çocuk-lar, the last stem vowel is back u, so -lAr → -lar. In ev-ler, the last vowel is front e, so -lAr → -ler. You did not memorize "-ler" and "-lar" as two words; you wrote -lAr and read off the answer.
The dative case is written -(y)A, another two-way suffix:
Yarın sabah okula erken gitmem lazım.
I need to go to school early tomorrow morning.
Akşam yemekten sonra eve yürüdük.
After dinner we walked home.
Okul-a (back u → a), ev-e (front e → e). The (y) in -(y)A only shows up when the stem ends in a vowel, as a buffer consonant: araba + -(y)A → arabaya.
I = i / ı / u / ü (the four-way vowel)
Capital I is harder because you have to check two things about the last stem vowel: is it front or back, and is it rounded or unrounded? Those two yes/no questions give four combinations, and each picks a different high vowel:
| Last stem vowel is… | I surfaces as | Example stem |
|---|---|---|
| front, unrounded (e, i) | i | ev → evi |
| back, unrounded (a, ı) | ı | kız → kızı |
| back, rounded (o, u) | u | okul → okulu |
| front, rounded (ö, ü) | ü | göz → gözü |
The accusative case is written -(y)I. Watch the same formula generate all four:
Anahtarı çantamda unutmuşum.
It turns out I left the key in my bag.
Bu sabah otobüsü kaçırdım, taksiyle geldim.
I missed the bus this morning and came by taxi.
Anahtar-ı (back unrounded a → ı), otobüs-ü (front rounded ü → ü). And with the (y) buffer after a vowel-final stem:
Kapıyı kapatır mısın, dışarısı çok soğuk.
Could you close the door? It's very cold outside.
Kapı ends in a vowel, so -(y)I brings in its y: kapı-y-ı. The high vowel itself is ı because the last stem vowel is back unrounded ı.
D = d / t (the assimilating consonant)
Some suffixes start with capital D. It comes out as d after a voiced sound and hardens to t after a voiceless one — the consonants p, ç, t, k, s, ş, h, f. The locative case is written -DA, combining a capital consonant and a capital vowel:
Bütün gün evde kaldım, hiç dışarı çıkmadım.
I stayed home all day and didn't go out at all.
Kitapta aradığın bilgi yok, internete bak.
The information you want isn't in the book; check online.
In ev-de, the stem ends in voiced v, so D → d; the vowel is e (two-way, front). In kitap-ta, the stem ends in voiceless p, so D → t, and the back vowel makes A → a. One formula, -DA, four possible spellings: de, da, te, ta. The matching hardening rule for C → ç is covered on the suffix-hardening page.
Putting it together: -DIr
The suffixes stack their choices independently. Take the (often formal) copula -DIr ("it is / presumably is"), which has a capital consonant and a capital high vowel:
Tren tam saat dokuzda kalkar; her sabah dakiktir.
The train leaves at exactly nine; it's punctual every morning.
Bu kelime büyük ihtimalle Farsça kökenlidir.
This word is in all likelihood of Persian origin.
In dakik-tir, the stem ends in voiceless k (so D → t) and its last vowel is front unrounded i (so I → i). In kökenli-dir, it ends in a voiced vowel (D → d) with front unrounded i (I → i). You never learned "-tir," "-dir," "-tır," "-dır," "-tur," "-dur," "-tür," "-dür" as eight words — you learned -DIr and computed.
Why this beats memorizing surface forms
English suffixes are essentially fixed: the plural -s is -s whether you bolt it onto cat or dog (yes, the sound differs, but you never write catz). Coming from that, learners instinctively try to memorize Turkish suffixes as fixed strings too — and end up storing four, six, or eight versions of one ending. Archiphoneme notation says: store one version with the variable parts capitalized, and let two small rules (vowel harmony, voicing assimilation) do the rest. This is not a textbook abbreviation you can ignore; it is how the language is actually organized in a fluent speaker's head, which is why every suffix in this guide is written this way.
Sözlükte bu fiilin nasıl çekildiğine bakalım.
Let's look up in the dictionary how this verb is conjugated.
Common mistakes
❌ EvlAr çok pahalı.
Incorrect — capital A copied onto the page as a letter.
✅ Evler çok pahalı.
The houses are very expensive.
Capital A, I, D never appear on the page. They are instructions to choose; you write the chosen letter — here A → e after the front vowel e, giving evler.
❌ Kitapı masaya koy.
Incorrect — capital I read as i/ı only, ignoring the formula's full set.
✅ Kitabı masaya koy.
Put the book on the table.
Two errors at once: -(y)I here is -ı (back unrounded a), and the stem-final p softens to b before the vowel.
❌ Otobüsda bekliyorum.
Incorrect — capital A forced into a four-way choice and D not hardened.
✅ Otobüste bekliyorum.
I'm waiting on the bus.
-DA after voiceless s hardens to -te; the front vowel ü makes A → e, never a.
❌ Gözi çok güzel.
Incorrect — capital I left as i instead of rounding to ü.
✅ Gözü çok güzel.
Her eyes are very beautiful.
The last stem vowel ö is front and rounded, so capital I → ü, not i. This is the rounding step learners skip most.
Key takeaways
- Capital letters in a suffix are placeholders, never letters to write.
- A = {e, a}, chosen by frontness only — two outcomes.
- I = {i, ı, u, ü}, chosen by frontness and rounding — four outcomes.
- D = {d, t} and C = {c, ç}, chosen by the voicing of the preceding sound.
- (y) is a buffer consonant that appears only after a vowel.
- Writing a suffix once — -lAr, -(y)I, -DA, -DIr — and realizing it mechanically replaces dozens of memorized variants.
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- Two-Way Harmony: e / aA1 — The simpler half of vowel harmony: low-vowel suffixes (notated capital A) surface only as e after front stems and a after back stems — frontness is the only thing that matters.
- Four-Way Harmony: i / ı / u / üA1 — The high-vowel half of vowel harmony: suffixes notated capital I surface as i, ı, u, or ü, chosen by both the frontness AND the rounding of the last stem vowel.
- Suffix Hardening: the D and C ArchiphonemesA2 — The mirror image of softening — a suffix-initial D hardens to t and a suffix-initial C hardens to ç after a voiceless stem, so the locative is kitapta (not *kitapde) and the past is gitti (not *gitdi).
- Buffer Consonants y, n and sA2 — The three epenthetic consonants that break up illegal vowel sequences when a vowel-initial suffix meets a vowel-final stem.