the ending -si in hangisi is a bit different. this ending is also used to turn some adjectives into pronouns
hangi (which) - hangisi (which one / which of them)
bazı (some) - bazısı (some of them)
birçok (many) - birçoğu (many of them)
it comes from onların hangisi (which of them) but onların is optional because -si already implies that
Hangi-(si)-,the possesive here accounts for the dog(noun),If we remove the suffix we have to add the dog: Hangi köpek senin?(Which dog is yours)
And I figured out what you are trying to do now,at least I am assuming: Köpeğin hangisi senin?(Which one of the dogs is yours?)
Köpek-in- hangisi senin---> -in- suffix is not a possesive,it is the suffix for ''of which'' dogs. Hope it is clear,hit me up if you have any questions!Cheers!
Just 2-3 sentences earlier in this same exercise, a sentence that's virtually identical had something like: Hangisi onun kopegi (excuse the wrong characters). I was confused by the possessive suffixes then, but am confused even more so now. This one (above) seems to make more sense, but I don't know why.
The tips and notes are a bit confusing because there is only one English example... The question word will go where the answer would be if it were a statement instead of a question. That sounds really confusing, I think, but here are some examples that may help:
kim? --> Bu
Kimelma yer? -->
neyer? --> Duo
This page from TurkishClass is about different types of questions. Section 2- Regular Questions will explain this in more detail:
Because its meaning would be different if it came before the word 'köpek'.
Hangi köpek senin: Which dog is yours?
Hangisi senin köpeğin/Senin köpeğin hangisi: Which is your dog?
With a few more examples:
O benim kitabım: That is my book.
O kitap benim: That book is mine.
Bu onların düşüncesi: This is their opininon.
Bu düşünce onların: This opinion is theirs.
Bunlar sizin çantalarınız: These are your bags.
Bu çantalar sizin: These bags are yours.