Dưới đây là các lỗi sai trong từng câu và cách sửa chúng:

1. **You must have be surprised when you heard the news.**
**Sửa:** You must have **been** surprised when you heard the news.

2. **You needn’t have do all this work.**
**Sửa:** You needn’t have **done** all this work.

3. **The window must have been broken on purpose.**
**Sửa:** Câu này đúng, không cần sửa.

4. **You must tired after working so hard.**
**Sửa:** You must **be** tired after working so hard.

5. **One of the men may have died on the mountain.**
**Sửa:** Câu này đúng, không cần sửa.

6. **You must been driving too fast.**
**Sửa:** You must have **been** driving too fast.

7. **The thief must have come in through the window.**
**Sửa:** Câu này đúng, không cần sửa.

8. **If he is not in the office, he must at home.**
**Sửa:** If he is not in the office, he must **be** at home.

Vậy, những câu sửa lại sẽ là:

1. You must have **been** surprised when you heard the news.
2. You needn’t have **done** all this work.
3. (Không cần sửa)
4. You must **be** tired after working so hard.
5. (Không cần sửa)
6. You must have **been** driving too fast.
7. (Không cần sửa)
8. If he is not in the office, he must **be** at home.