You must cultivate your mind.
You must build up your courage.
You must perform your duty.
You should school yourself to be patient.
You should reflect.
You must look after the child.
You should prepare your lessons.
I can't wait for you.
You should learn how to control your emotions .
You must control yourself.
You need a haircut.
I have to learn from watching you.
You'll have to manufacture some kind of excuse.
You should learn how to control your moodiness.
You must practice grammar.