一、指代物

it可替代動植物與無生命的東西，它與one的區別在于one= a/an + none; it = the + n。

1. ---Where is my pencil case? ---Isn’t it in your backpack?

2. ---I have a motorbike. It (= the motorbike) was bought threeyears ago.

3. As this chair is broken, I must have it (= the chair) repaired.

4. My father bought a pen and gave it (= the pen) to me.

5. You can not eat your cake and have it. 世事難兩全。

試比較：

6. I have no dictionary, so I want to buy one. (one = a dictionary)

7. I have a dictionary, it is over there. (it = the dictionary)

二、指代人

it可指代一個未親眼看到的、不明身份性別的、面目不詳的人，或嬰兒、兒童，照片中的人物等。

8. --- Who is there waving to you? ---It’s my friend Tom.

9. ---Who is crying in the room? ---It’s my brother Jack.

10. ---Who is knocking at the door? ---It must be Kate, my classmate.

11. ---Who is the girl in the photo on the wall? ---It’s my sister.

12. ---Who is it? ---It’s me. (有人敲門)

13. ---Someone is ringing the doorbell. Go and see who it is. (敲門)

14. ---Oh, by the way, there is a telephone call for you. ---Who was it? (打電話)

15. ---Who is making so much noise? ---It must be the children.

16. There is a person knocking at the door. Who can it be?

17. Just at that time, in came a girl. It was Mark’s sister.

18. There is a young lady at the door. It is his daughter.

19. What a beautiful baby! Is it a boy?

20. A baby is lying in the cradle. It was born two months ago.

21. The baby cry because it is hungry.

22. The baby has got its first tooth.

注意：若身份已確定則要用人稱代詞。

23. There is a lady at the door. She wants to see you.

注意：向別人介紹某人時用this。

24. This is my friend, Jim.