Change it into passive voice.
Sally decorated the living room.
They send text messages every day.
They sent Paul a letter from Italy.
Tom takes the children to school.
Alex cooked dinner last night.
A van hit John's car.
Did Rosalie bake the cake?

Passive voice is when the subject of the sentence is acted on by the verb. Since these sentences are all in active voice, we must change them to passive voice.

1. The living room was decorated by Sally.

2. Text messages are sent by them everyday.

3. Paul was sent a letter from Italy by them.

4. The children are taken to school by Tom.

5. Dinner was cooked by Alex last night.

6. John's car was hit by a van.

7. Was the cake baked by Rosalie?

because each is self-sufficient.  

and your question what topic are you in trouble with?