Learn Turkish: Kutuda hiç şişe yok. - There are no bottles in the box.

In Turkish, nouns that follow numbers or quantity words always stay in the singular form. Just as you say iki şişe (two bottles) without the plural suffix, you also keep the noun singular after hiç (none/any).

Could I just say Kutuda şişe yok without using hiç?

Yes, Kutuda şişe yok simply means "There are no bottles in the box." Adding hiç emphasizes the lack of quantity, making it mean "There aren't any bottles" or "There are no bottles at all."

How does this sentence connect to the question word kaç (how many)?

This sentence is a perfect zero-quantity answer to a kaç question! If someone asks Kutuda kaç şişe var? (How many bottles are in the box?), you would use this exact sentence to tell them the answer is zero.

Why is it kutuda instead of just kutu?

Kutu means "box". The suffix -da is the locative suffix, which means "in", "on", or "at". Attaching it creates kutuda, meaning "in the box".