you don't know how to
Ты не умеешь кататься на велосипеде?
You don't know how to ride a bicycle?
You don't know how to lose.
В чём дело, ты не умеешь открывать дверь?
What's the matter, you don't know how to open the door?
— Двойная страховка (1944)
You don't know how to kiss.
Can't you sing?
Can't you do this?