no

"No" is the most fundamental word for negation in Turkish. It functions as a direct refusal or a way to indicate that something does not exist or is not the case. The mental image is a simple, firm stop or a clear "not that." In conversation, "hayır" is the standard, polite way to say no. However, in very casual speech, you will often hear "yok" used to mean "there isn't" or "no" (as in "no, that's not happening"). "Hayır" is used for rejecting an offer, while "yok" is used for non-existence or lack of availability.
In conversation
Refusing an offer
Kahve ister misin?
Do you want coffee?
Hayır, teşekkürler.
No, thank you.
Use 'hayır' when declining an invitation or offer.
Checking availability
Ekmek var mı?
Is there any bread?
Yok, bitti.
No, it's all gone.
'Yok' is the go-to word when something is out of stock or does not exist.
Examples
Hayır, gitmiyorum.
No, I am not going.
Daha fazla vaktim yok.
I don't have any more time.
Hayır, bu kesinlikle kabul edilemez.
No, this is absolutely unacceptable.