1. The boy visited his uncle last month.
- It was the boy who visited his uncle last month.
2. My mother bought me a present on my birthday.
- It was my mother who bought me a present on my birthday.
3. Huong and Sandra sang together at the party.
- It was Huong and Sandra who sang together at the party. (They were Huong.)
4. Nam’s father got angry with him.
- It was Nam's father who got angry with him.
5. The boys played football all day long.
- It was the boys who played football all day long.
6. The girl received a letter from her friend yesterday.
- It was the girl who received a letter from her friend yesterday.
7. His presence at the meeting frightened the children.
- It was his presence at the meeting that frightened the children.