I need to find out who pen this is.
I need to find out whose pen this is.
I'm not sure how often cleans the house the cleaning lady.
I'm not sure how often the cleaning lady cleans the house.
They went to the same restaurant that Mark had been to it.
They went to the same restaurant that Mark had been to.
I want to know how many time we need.
I want to know how much time we need.
I don't remember which she said.
I don't remember what she said.
Do you know if are there any English classes at this school?
Do you know if there are any English classes at this school?
Most of the people suggested that their children shall go to school earlier.
Most of the people suggested that their children should go to school earlier.
Yesterday she asked me if you will go to the concert with her.
Yesterday she asked me if you would go to the concert with her.