Learn Turkish: Bu hediye kimin için?

When the postposition için (for) is used with personal pronouns or the question word kim (who), it requires the genitive "owner" ending. So, kim becomes kimin. You can think of it as literally saying "for whose".

Why is için at the very end of the sentence?

Turkish uses postpositions instead of prepositions. This means words like için always come immediately after the noun or pronoun they attach to. Instead of saying "for who", Turkish naturally groups it as "who for" (kimin için).

Where is the word for "is" in this sentence?

There isn't one! In Turkish, simple statements or questions describing what something is in the present tense often don't need an explicit verb when the subject is a third-person thing like bu hediye (this gift). The "is" is simply understood from context.

Could I change the word order and say Kimin için bu hediye?

Yes, people would perfectly understand you because Turkish word order is flexible. However, Bu hediye kimin için? is the most standard order. In Turkish, the most important information (here, the question phrase kimin için) is usually placed right before the verb, or at the end of the sentence if there is no explicit verb.