Ability and Possibility: -(y)Abil

To say "I can come" in Turkish, you fuse two verbs into one word: the main verb stem plus the little auxiliary bil- ("to know"), which here has bleached into a pure "be able to" marker. The whole package is -(y)Abil, the abilitative, almost always sitting in the aorist: gelebilirim "I can come," yapabilirsin "you can do it." This one structure covers both senses English splits between can (ability) and may/might (permission and possibility). The catch — and the thing that surprises every learner — is the negative: you do not simply add the usual "not." Inability has its own irregular form, -(y)AmA, which we introduce here and treat in full on the inability page.

The form: stem + -(y)Abil + aorist + ending

Build it in layers. Take the verb stem, add -(y)Abil (the y is a buffer after a vowel), then the aorist -Ir, then the Type-1 personal ending:

The -(y)Abil part harmonizes two ways (a / e): gel-ebil-, yap-abil-. After a vowel-final stem you insert the buffer y: oku-y-abil-, anla-y-abil-, bekle-y-ebil-. The auxiliary bil is fixed (it never harmonizes its own vowel), and the aorist on it is regular: -ir here because bil ends in a consonant after a single-vowel-class root — practically, you can memorise "-(y)Abilir" as a chunk and just add the personal ending.

Two meanings in one: 'can' and 'may'

English keeps can (ability) separate from may / might (permission and possibility). Turkish does not — -(y)Abil carries the whole spread, and context decides the reading:

The first is ability (a skill I possess), the second is permission (asking whether it's allowed), the third is possibility ("might"). All three are the same suffix. When you specifically want possibility/permission rather than learned skill, the aorist form is the default; for actual present capability in progress you'll often hear the continuous -(y)Abiliyor (konuşabiliyorum "I can / am able to speak"), as in the first example.

Questions and the aorist question particle

To ask "can you...?", the question particle mI splits off after the aorist and carries the personal ending: yapabilir misin? "can you do it?", gelebilir miyim? "may I come?". The particle is written as a separate word and harmonizes (mı / mi / mu / mü):

This is the standard polite request frame in Turkish — far more common than barking an imperative. -(y)Abilir misin? is the everyday "could you...?"

The negative is NOT a regular 'not'

Here is the trap. You might expect "I can't come" to be gelebilmem — abilitative plus the usual verbal negative -mA. It is not. Inability has a completely separate, irregular form: the auxiliary bil vanishes, and the stem takes -(y)AmA instead:

So gelebilirim "I can come" → gelemem "I can't come" (not gelebilmem); *anlarım patterns aside, the inability of anlamak is anlayamadım "I couldn't understand," with the buffer y after the vowel. The negative drops bil entirely and uses -(y)AmA, which then takes whatever tense you need — present continuous gelemiyorum "I can't come (right now)," past gidemedi "couldn't go," aorist gidemem "I can't go." This is treated step by step on the inability page; the one rule to lock in now is: never negate by keeping bil.

-(y)Abil with other tenses

Although the aorist is the home base, -(y)Abil can sit on a future or past too, shifting the time of the possibility:

Here gidebiliriz keeps the aorist for a future-leaning possibility, while koşabilirdim ("I could / used to be able to run") is -(y)Abil + aorist + past copula -DI — the past-ability form. Note this is distinct from the inability past koşamadım "I couldn't run (on one occasion)."

Common mistakes

The headline error is negating the abilitative the "logical" way. There is nothing logical here to lean on — bil disappears and -(y)AmA takes over. Memorise the pair gelebilirim / gelemem.

The thread: insert the buffer y after vowels (okuyabilirim, anlayamadım), split the question particle off correctly (yapabilir misin?), and never form inability as -(y)Abil + -mA.

Key takeaways

• -(y)Abil = "can / be able to / may / might" — one structure for English can, may, might, could.
• Build it as stem + -(y)Abil + aorist + ending; memorise -(y)Abilir as a chunk: gelebilirim, yapabilirsin.
• The y is a buffer after vowel stems: okuyabilirim, anlayabilirim.
• Questions use the split particle mI: yapabilir misin?, gelebilir miyim? — the standard polite "could you?".
• The negative is the irregular -(y)AmA, which drops bil: gelemem "I can't come," anlayamadım "I couldn't understand" — never *gelebilmem.
• It is ability/possibility, not obligation — don't confuse it with the necessitative -mAlI. For can versus the impersonal mümkün "it's possible," see the decision guide.