Learn Turkish: Hiç soru yok. - There are no questions at all.

In Turkish, when you use a word that means zero or none, like hiç, the noun that follows it stays singular. You don't need to add the plural ending -lar, so we say hiç soru instead of hiç sorular.

Can I just say Soru yok without hiç? What's the difference?

Yes, you can! Soru yok simply means 'There are no questions.' Adding hiç emphasizes the negative, changing the meaning to 'There are no questions at all' or 'There is not a single question.'

If hiç implies 'none', why do we also use yok? Isn't that a double negative?

It is a double negative, and that is exactly how Turkish grammar works! The word hiç (at all / any) almost always requires a negative word like yok (there is not) or a negative verb to complete the meaning.

Can I use hayır instead of yok to say 'no questions'?

No, hayır just means 'no' when you are directly answering a yes/no question. Whenever you want to say that something does not exist or that 'there is no [thing]', you must use yok.