Learn Turkish: Hangi ayakkabıda indirim var?

In Turkish, to say that an object "has" something, you often attach a locative suffix (-da or -de, meaning "in" or "on") to the object, and then use var. So ayakkabıda indirim var literally translates to "on the shoe there is a discount."

Does the question word hangi (which) change endings to match the noun it describes?

No, when hangi is placed directly in front of a noun like ayakkabı, it acts as a descriptive word and never changes. The noun it describes can take suffixes (like the -da we see here), but hangi stays exactly the same.

Why isn't there a yes/no question particle like mı or mi at the end of the sentence?

Because the sentence already contains a specific question word: hangi (which). In Turkish, you only add a yes/no question particle when the sentence doesn't already have a question word in it.

Can I use ayakkabı (shoe) in the singular here, even if I mean a pair of shoes?

Yes! In Turkish, words for things that naturally come in pairs, like shoes or eyes, are frequently used in the singular. Ayakkabı can refer to a single shoe, a pair of shoes, or just footwear as a general category.