1.Найдите и исправьте ошибку в каждом предложении. Find and correct the

1.Найдите и исправьте ошибку в каждом предложении. Find and correct the mistake in each sentence.
1. There were a pencil on the table.
2. There was three boys in the classroom.
3. Was a woman there in the caf?
4. Were two chairs there at the window?
5. There not was a computer on the table.
6. There not were three pens in the bag.
7. There were a dog in the room.