In order to express the ability to do something you just need another suffix. But in Turkish you have to differ the ability to do something: either you are generally able to do something (skill, knowledge) or just at the moment (situational).

16.1.1 The General Ability

-(y)ebiliyor oder -(y)abiliyor (Little Vowel Harmony).
The y in bracks is only inserted when the word ends on vowel. Then you add a personal pronoun suffix (by the way, the suffix is not changed into “-(y)abılıyor”, though there is a vowel “a” before):

 = I can do
yapabiliyorsun = you can do
yapabiliyor = he/she/it can do
 = we can do
yapabiliyorsunuz = you (plural or polite form) can do
yapabiliyorlar = they can do

Maybe you have noticed that the suffix has a similarity to the verb  bilmek in 3rd person singular (biliyor = he/she/it knows). A free translation of the suffix could be “knowing to do something” and in general  bilmek is translated with “to know, to be able”.

Another example:
gidebiliyorum = I can walk
gidebiliyorsun = you can walk
gidebiliyor = he/she/it can walk
 = we can walk 
gidebiliyorsunuz = you (plural or polite form) can walk 
gidebiliyorlar = they can walk 

The verb stem of gitmek is git-, but as you know you have to soften t to d.

As mentioned before this kind of ability expresses a skill or knowldege:
Türkçe konuşabiliyorum. = Ich can speak Turkish./I know Turkish.

16.1.2 Negation of General Ability

Now the suffix has to be modified: remove -bil- and insert an m so you’ve got: -emiyor or -amiyor (Little Vowel Harmony

yapamıyorum = I can’t do 
yapamıyorsun = you can’t do
yapamıyor = he/she/it can’t do
yapamıyoruz = we can’t do
yapamıyorsunuz = you (plural or polite form) can’t do
yapamıyorlar = they can’t do

16.1.3 The Situational Ability

If you are able to do something because you want to do it and no external circumstance prevents it, then you use the suffix:
 or -(y)ebilir (Little Vowel Harmony)

yapabilirim = I can do (in this moment) 
yapabilirsin = you can do 
yapabilir = he/she/it can do 
yapabiliriz = we can do 
yapabilirsiniz = you (plural or polite form) can do 
yapabilirler = they can do 

16.1.4 Negation of Situational Ability 

To negate the situational ability you need the suffix:
(y)eme(z) or -(y)ama(z) (Little Vowel Harmony).

As usual  y occurs at vowel ending and in each 1st person the z at the end is removed (remember the negation of ir-present):

yapamam = I can’t do (in this moment)
 = you can’t do
yapamaz = he/she/it can’t do
yapamayız = we can’t do
yapamazsınız = you (plural or polite form) can’t do
 = they can’t do

It’s important to note be aware of the nie Nuance: yapamam = “I can’t do” expresses that I cannot do something because I don’t want to or a particular circumstance is preventing me from doing it.

gidemem = I can’t walk 
gidemezsin = you can’t walk 
gidemez = he/she/it can walk
gidemeyiz = we can’t walk
 = you (plural or polite form) can’t walk 
gidemezler = they can’t walk

Meaning: I can’t or don’t walk to somewhere in this moment.


In Turkish you can use the situational ability to express the allowance of doing something, as there is no explicit verb for this (like for example “may” in English). 

Sana bir şey sorabilir miyim? 
= May I (Am I allowed to) ask you something?
Girebilirsin. = You may (are allowed) come in.
Bakabiliriz. = We may (are allowed) to watch. 

bilmek = to know, to be able; bilgi = the knowledge; bilgisayar = the computer (literally: the counter of knowledge); çeviri = the translation; çevirmek = to translate; hesap (or: fatura) = the bill, the invoice, the check; hesaplamak = to calculate; saymak = to count; tercüme = the translation; tercüme etmek = to translate