Cách sử dụng các liên từ chỉ thời gian when, while, before, by, as, after

When, while, before, by, as, after là các liên từ chỉ thời gian.

Chúng ta sẽ sử dụng các liên từ này khi nào? Sử dụng các liên từ này như thế nào sao cho đúng ngữ pháp và đảm bảo ngữ nghĩa của câu rõ ràng?

Hãy cùng ENGZY giải đáp những câu hỏi ấy.

1. Công thức:

Eg: Jim was standing  under the tree       when he heard an explosion.

(Jim đang đứng dưới gốc cây xảy ra trước)

Eg: The boy fell and hurt himself        while he was riding a bicycle.

(Cậu bé bị ngã và bị đau xảy ra sau)

Eg: Before I came to her home,          she had gone to work.

(Sau before phải là quá khứ đơn)

Eg: After we had finished our test,             we handed in for teacher.

(Sau after phải là thời quá khứ hoàn thành)

Eg: As I came she was leaving home.

2. Ý nghĩa:

• Các liên từ chỉ thời gian: when, while, before, by, as, after nối câu giữa các thời quá khứ đơn, quá khứ tiếp diễn và quá khứ hoàn thành.

CÔNG THỨC ĐƠN GIẢN NHẤT CHO 12 THÌ TRONG TIẾNG ANH

3. Vị trí và cách dùng:  

• Vị trí linh hoạt trong câu, tùy theo hàm ý nhận mạnh, hay diễn đạt của người sử dụng. Mệnh đề có chứa liên từ When, While, Before, By, As, After là mệnh đề trạng ngữ chỉ thời gian phụ bổ sung ngữ nghĩa cho mệnh đề chính.

• Khi được đảo lên đầu câu When, While, Before, By, As After cần ngăn cách với mệnh đề chính bằng dấu phẩy.  

  Eg: Before I went home, I had met my friends at school.

  Eg: After I had finished my work, I rushed to the market to buy food for dinner.

  Eg: I had cooked dinner as my mother went on business yesterday.

• Bên cạnh vai trò liên từ, When, While, Before, By, As, After đều là những giới từ, có thể theo sau bởi danh từ, cụm danh từ.

  • Eg: Before going to bed, she had finished her homework. = She had finished her homework before going to bed.
  • Eg: After graduating from university, she apply for an accountant.

• Ngoài vai trò liên từ trong các mệnh đề, When, While, Before, By, As, After còn xuất hiện trong các câu trúc đặc biệt dưới dạng đảo ngữ:

  • Hardly/ Scarely + had + S + had + V_{3/ ed} +…when + S + V_{2/ ed} + … :Vừa mới…. thì….

    • Eg: Hardly had they went home when it rained heavily 
    • Scarely mother had cleaned up when the boy messed up.

4. Luyện tập:

1. I (call) …… Mr Wilson at 9 last night, but he (not be) ……at home. He (study) …..at the library.
2. I (not hear) ……… the thunder during the storm last night because I (sleep) ……..
3. It was beautiful yesterday when we went for a walk in the park. The sun (shine) ….. The birds (sing) ……..
4. My brother and sister (talk) about something when I (walk) …..into the room.
5. Tom went to his friends ‘house, but the boys (not be) …. there. They (play) ……soccer in the vacant lot down the street.
6. The little boy (fall) …….. asleep while his mother (read) ……. him a story.
7. ….. they (wait) …… for me when I (arrive) ………at the station?
8. She (swim) ….. in the sea when I (see) ……. her.
9. ……they (play) ……..tennis when it (start)…….raining?
10. We (drive) ………home from the theater when the police (stop) ……..us.
11. The wind (blow)….. very hard when I (go) …….out this morning.
12. They (come) …………….. back home after they (finish) ………………… their work.
13. She said that she (meet) ……………………. Mr. Bean before.
14. Before he (go) ………………….. to bed, he (read) ………………… a novel.
15. He told me he (not/ wear) ………………… such kind of clothes before.
16. When I came to the stadium, the match (start) ………………………………….
17. Before she (listen) ………….. to music, she (do)……………. homework.
18. Last night, Peter (go) ……….. to the supermarket before he (go) ………… home.

Key 

1.  was calling – was not – was studying
2. did hear – was sleeping
3. was shining – were singing
4. were talking – walked
5. were not – were playing
6. felt – was reading
7. were ..waiting – arrived
8. was swimming – saw
9. were …playing – started
10. were driving – stopped
11. was blowing – went
12. came – had finished
13. had met
14. went – had went
15. had not worn
16. had started
17. listened – had done
18. had gone – went