It was known to me that the work had been done by him
It was known to me that the work has been done by him
It is known to me that the work was done by him
It was known to me that the work was done by him
The problem is solved by you.
You are solved with the problem.
Let the problem be solved by you.
Let you solve the problem.
Let a song sing by him.
Let a song be sung by him
Let a song be sang by him
Let a song sung by him
By whom will you be helped?
By whom you will be helped?
By whom would you be helped?
By whom you would be helped?
Is he known by you?
Is he known to you?
Is he knew by you?
Was he known by you?
The books have been bought by me.
The books had been bought by me.
The books were bought by me.
The books are bought by me.
Let a song be sang by him.
Let a song sing by him.
Let a song sang by him.
Let a song be sung by him.
Is they known by you?
Are they known with you?
Are they known by you?
Are they known to you?