We can use a noun after what, which, whose, how many and how much.They are discussing which colour to paint the walls. You can ask your parents how much money to take with you. 我们可以在what,which,whose,how many和howmuch等疑问词后跟一个名词，再跟动词不定式。We can also use an adjective like sure or clear before a question word.Suzy was not sure who to ask for help. Are you clear when to meet at the gate tomorrow? 我们可以在sure和clear这样的形容词后跟疑问词加动词不定式。