1. I have heard her sing this song this several times.

She has been heard to sing this song several times

2. People saw him steal your car.

He was seen to steal your car

3. The teacher is watching the work.

The work is being watched by the teacher

4. He won't let you do that silly thing again.

You won't be let do that silly thing again. (You won't be allowed to do .....)

5.People don't make the children work hard.

The children aren't made to work hard.

6. They made him work all day.

He was made to work all day

7.The detective saw the woman putting the jewelry in her bag.

The woman was seen putting the jewelry in her bag