English splits "can" (ability/permission) from "may/might" (possibility/likelihood), but Turkish bundles a remarkable amount of that range into a single suffix, -(y)Abil. Layered on top are two lexical options: the adjective mümkün ("possible"), which states the abstract possibility of an event, and olabilir ("it may be"), which hedges how likely something is. The most common mistake learners make is reaching for mümkün where a native speaker would just use -(y)Abil. This page sorts out which tool fits which job; the full suffix paradigm is on the abilitative -(y)Abil page, the negative on the abilitative negative page, and the related epistemic -DIr on the inference with -DIr page.
The workhorse: -(y)Abil does the heavy lifting
The suffix -(y)Abil attaches to a verb stem (with a buffer y after a vowel) and covers three English notions in one form: ability ("can / be able to"), permission ("may / be allowed to"), and possibility ("might"). Context disambiguates.
Üç dil konuşabiliyorum: Türkçe, İngilizce ve biraz Almanca.
I can speak three languages: Turkish, English, and a little German.
That's ability. The same suffix, in a question to someone in authority, becomes permission:
Müdür bey, bir saat erken çıkabilir miyim?
Sir, may I leave an hour early?
And in a statement about an uncertain event, it becomes possibility:
Trafik yüzünden biraz geç kalabilirim, beni bekleme.
I might be a bit late because of the traffic — don't wait for me.
One suffix, three jobs. English speakers under-use it precisely because no single English word stretches this far.
-(y)Abil for almost everything in the "can / may / might" zone. The lexical words mümkün and olabilir are specialists, not the everyday choice.The buffer y: spelling -(y)Abil correctly
After a consonant the suffix is just -Abil (gid-ebil-irim, yap-abil-irim). After a vowel, a buffer y slots in so two vowels don't collide: oku → oku-y-abil-irim ("I can read"), bekle → bekle-y-ebil-irim ("I can wait"). The vowel of the suffix follows front/back harmony: -abil after back vowels, -ebil after front vowels.
Bu kelimeyi okuyabilir misin, benim gözlüğüm yanımda değil.
Can you read this word? I don't have my glasses on me.
When to use mümkün: stating that an event is possible (abstractly)
mümkün is an adjective meaning "possible." You use it to assert that an action or outcome is feasible / is a possibility in the abstract, typically with the -mAk infinitive ("X-ing is possible") or as a standalone comment.
Bu saatte oraya yürüyerek gitmek mümkün mü?
Is it possible to walk there at this hour?
Elbette, her şey mümkün.
Of course — anything's possible.
The crucial difference from -(y)Abil: mümkün is about the feasibility of the event as such, detached from a particular subject's ability. "Gidebilir miyim?" asks whether I can/may go; "Gitmek mümkün mü?" asks whether the going is possible at all. They overlap, but where you'd naturally make a person the subject, the suffix is more idiomatic — which is exactly the spot where learners wrongly default to mümkün.
When to use olabilir: hedging likelihood ("maybe / it may be")
olabilir is literally "it can be / it may be" — the -(y)Abil suffix already living on the verb olmak. As a fixed expression it hedges the likelihood of a whole proposition: "maybe," "possibly," "that may well be." It's the go-to for guessing and softening claims.
Telefonuna bakmıyor — belki uyumuş olabilir.
He's not answering his phone — maybe he's fallen asleep.
Haklı olabilirsin ama yine de kontrol edelim.
You may be right, but let's check anyway.
olabilir comments on how probable a situation is, often standing in for a whole clause, whereas -(y)Abil on a lexical verb says a specific person might do that specific action. They frequently co-occur, as in uyumuş olabilir ("he may have fallen asleep"), where olabilir hedges the inference about his state. For the closely related inferential -DIr ("he's probably asleep"), see the inference with -DIr page.
-(y)Abil = "X can/might happen"; mümkün = "X is possible"; olabilir = "maybe / it may be that X." The last two comment on a proposition; the suffix lives inside the verb.Quick comparison
| Tool | Core job | Example | Gloss |
|---|---|---|---|
| -(y)Abil | ability | yüzebilirim | I can swim |
| -(y)Abil | permission | girebilir miyim? | may I come in? |
| -(y)Abil | possibility | gecikebilirim | I might be late |
| mümkün | abstract feasibility of an event | gitmek mümkün | it's possible to go |
| olabilir | hedged likelihood of a proposition | doğru olabilir | it may be true / maybe |
Negation is irregular — flag it
The negative of -(y)Abil is not a simple negation; ability "cannot" uses a separate -(y)AmA form: yüzebilirim ("I can swim") → yüzemem ("I can't swim"). And "might not / may not" (negated possibility) is yet another shape, -mAyAbil: gelmeyebilir ("he might not come"). These don't map onto the positive in a tidy way, so they get their own treatment on the abilitative negative page — just know now that "I can't" is not built by sticking a negative onto -(y)Abil.
Maalesef bu akşam gelemem, çok işim var.
Unfortunately I can't come this evening — I have a lot of work.
Common mistakes
The dominant error is using mümkün where -(y)Abil is the natural, idiomatic choice.
❌ Mümkünüm sana yardım etmek.
Incorrect — mümkün is not conjugated for a person; a person's ability uses -(y)Abil.
✅ Sana yardım edebilirim.
I can help you.
❌ Pencereyi açmak mümkün müsün?
Incorrect — mümkün can't take a personal ending; ask permission with -(y)Abil.
✅ Pencereyi açabilir misin?
Can you open the window?
❌ Yarın yağmur yağabilir mümkün.
Incorrect — don't stack the -(y)Abil possibility and mümkün; pick one.
✅ Yarın yağmur yağabilir. / Yarın yağmur yağması mümkün.
It might rain tomorrow. / It's possible it'll rain tomorrow.
❌ Yüzebilmem.
Incorrect negative of ability — 'I can't swim' is yüzemem, not a negated -(y)Abil.
✅ Yüzemem.
I can't swim.
A subtler point: olabilir is for hedging likelihood, not for asking permission. "May I?" is -(y)Abil miyim?, never olabilir miyim?. Reserve olabilir for "maybe / that might be the case."
Key takeaways
-(y)Abilis the everyday workhorse: one suffix for ability, permission, and possibility — default to it.- Spell it with a buffer y after vowels (oku-y-abilir) and harmonise the vowel: -abil / -ebil.
mümkün= "(it's) possible" — abstract feasibility of an event, not conjugated for a person.olabilir= "maybe / it may be" — hedges the likelihood of a whole proposition.- The error to avoid: using
mümkün(or a personal ending on it) where Turkish wants-(y)Abil. - Negation is irregular: "I can't" is yüzemem, and "might not" is gelmeyebilir — not a plain negated suffix.
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Start learning Turkish→Related Topics
- Ability and Possibility: -(y)AbilA2 — The abilitative -(y)Abil means 'can, be able to, may' — gelebilirim 'I can come', yapabilir misin? 'can you do it?' — built from a verb stem plus the auxiliary bil- in the aorist; its negative is the special -(y)AmA, not a regular -mA.
- Inability: -(y)AmA ('cannot')B1 — The negative of the abilitative is the irregular -(y)AmA, which replaces -(y)Abil entirely and drops the auxiliary bil — gelemem 'I can't come', anlayamadım 'I couldn't understand', çıkamayız 'we can't get out' — then stacks with any tense.
- -mAlI vs gerek vs lazım: NecessityB1 — Three ways to say must, should, and need to in Turkish — when each one fits and how their grammar differs.
- Inference and Probability with -DIr and AdverbsC1 — How Turkish expresses confident guesses and degrees of probability — the suppositional -DIr ('must be / probably is'), epistemic -mAlI and -(y)Abilir, and the adverbs galiba, herhalde, kesin that grade certainty.