Translation:Sen tok musun?
why musin and not misin?
4-way vowel harmony applies to question particles (mi/mı/mu/mü/etc), so you have u's in musun because they come after the o in tok. (If you missed vowel harmony, it's introduced here: https://www.duolingo.com/skill/tr/Accusative )
of course! Its so obvious now, thanks for pointing it out me!!! :)
Why tok musunuz is incorrect?
Could you say 'sen mi toksun'?
What does it mean? that you are not hungry?
Right: it's that you're not hungry. That your stomach is full.
why 'sen tok musunuz?' is incorrect?
"Sen tok musun" is fine
"Siz tok musunuz" is fine
But you cannot mix up these two endings for these difference pronouns :)