How long have they waited for the doctor?
-> How long has the doctor been waited for?

What time can the boys hand in their papers?
-> What time can their papers be handed in by the boys?

who look after the children for you?
=>Who are the children looked after for you by?

How many marks does the teacher give you? .
How many Morks de the diacher quen you one you geven by the toachenr