Ngữ pháp - Mệnh đề trạng từ chỉ thời gian

ADVERBIAL CLAUSES OF TIME
MỆNH ĐỀ TRẠNG TỪ CHỈ THỜI GIAN

•  Mệnh đề trạng ngữ chỉ thời gian (adverbial clauses of time) là những mệnh đề bắt đầu bằng các liên từ chỉ thời gian như: when (khi, vào lúc), while,  as (trong khi), until, till (cho đến khi), as soon as, once (ngay khi), before, by the time (trước khi), after (sau khi),  as long as , so long as (chừng nào mà), since (từ khi) ...

Ví dụ: 
- When we were in New York, we saw several plays.
- I’ll phone you as soon as I get back from work.
- We stayed there until it stopped raining.

*     Lưu ý: Mệnh đề trạng ngữ chỉ thời gian có thể đứng đầu hoặc cuối câu. Nếu mệnh đề trạng ngữ chỉ thời gian đứng ở đầu câu sẽ ngăn cách với mệnh đề chính bằng dấu phẩy (comma).

* Cách diễn đạt thời tương lai trong các mệnh đề thời gian:

Ví dụ: 
- Bob will come soon. When Bob comes, we will see him.
- Linda is going to leave soon. Before she leaves, she is going to finish her work.         
- We’ll be able to leave for the airport as soon as the taxi arrives.
- I’ll wait here until they come back.

Lưu ý: Trong các mệnh đề trạng ngữ chỉ thời gian với ý nghĩa tương lai chúng ta không dùng thì tương lai đơn (will) hoặc be going to mà chỉ dùng thì hiện tại đơn (simple present) hoặc thì hiện tại hoàn (present perfect) khi muốn nhấn mạnh đến sự hoàn thành của hành động trước khi một hành động khác xảy ra.

Ví dụ: 
- I’ll go to bed after I finish my homework.
- I’ll go to bed after I have finished my homework.

* Cách diễn đạt thời quá khứ trong các mệnh đề thời gian:

Ví dụ: 
- She said goodbye before she left.
- I started school when I was six.
- We stayed there until we finished work.
- My mother went home after she finished work at the office.
- My mother went home as soon as she finished work at the office.

Ví dụ: 
- The telephone rang while we were having dinner.
- As I was walking home, it began to rain.
- I was cooking dinner while my husband was reading a book.
- He was talking on the phone when I arrived.

Ví dụ: 
- We haven’t met each other since we left school.
- I have played the piano since I was a child.

Ví dụ: 
- She got a job after she had graduated from university.
- She got a job as soon as she had graduated from university.
- She had left before he came.
- By the time he arrived, we had already finished work.