1. She is writing a letter now.

A letter is being written by her.

2. They speak French and English in Canada.

French and English are spoken in Canada.

3. Nam can’t do that math.

That math can't be done by Nam.

4. Wash your clothes.

Your clothes need to be washed.

5. They have repaired this road.

This road has been repaired by them.

6. It is thought that he is singer.

He is thought to be a singer.

7. It is said that he stole this car.

He is said to steal this car.

1. She is writing a letter now.

$\to$A letter is being written by her.

2. They speak French and English in Canada.

$\to$French and English are spoken in Canada.

3. Nam can’t do that math.

$\to$That math can't be done by Nam.

4. Wash your clothes.

$\to$Your clothes need to be washed.

5. They have repaired this road.

$\to$This road has been repaired by them.

6. It is thought that he is singer.

$\to$He is thought to be a singer.

7. It is said that he stole this car.

$\to$He is said to steal this car.