SỰ PHỐI HỢP GIỮA CÁC THÌ TRONG CÂU PHỨC (Sequence of tense)

$A -$ Sự phối hợp về thì trong mệnh đề chính phụ
(Mệnh đề phụ: mệnh đề chứa liên từ - liên từ nối)
                               MĐC                                                              MĐP
$1.$ Hiện tại đơn                                                         - Các thì hiện tại
                                                                                   - Các thì tương lai
                                                                                   - Thì quá khứ (kèm thời gian cụ thể): hiếm
ex: She says (that)  She often goes to work by bus.
                                   She is watching TV at the moment.
                                   She'll go to HN tomorrow.
      He never smokes while he's driving.
      Mary considers she'll be lying on the beach this time next year.
                                  she'll have repaired her house by that time.
                                 she'll have been learning English for  $5$  years by the end of this month.
      She says she met her former classmate at the cinema last night.

$2.$ Qúa khứ đơn                                    - Các thì QK (đơn, tiếp diễn, HTTD, HTHT, would + V,
                                                                                      dự định quá khứ)
                                                               - Hiện tại đơn (sự thật, chân lí)
ex: Nancy said she went to the zoo last Sunday.
                           she was watching TV at  $9$  p.m last Sunday.
                           she had visited her grandparents before she had her dinner last night.
                           she had been working this work for  $3$  months (up to last Thursday).
      She decided she was going to visit her parents that afternoon.
      I was taught that the sun is bigger than the moon.

$3.$ HTHT                                                     HTĐ  (TLĐ)
ex: We've just decided that |          we'll go to London tomorrow.
      He's found out that the road is very bumpy.

$4.$  QKHT                                                QKĐ(TL  trong  QK)
ex: He had expected that |             the test was earlier.
      They had just decided they would leave the next day.

$B - $  Sự phối hợp động từ trong câu phức có Mệnh đề trạng ngữ chỉ thời gian.
$I.$  Liên từ trong Mệnh đề thời gian
when, while, as, just as, as soon as, until, till, as long as (cho đến khí), since (+ QKĐ), before, after, by the time (that), no sooner...than, hardly...when, scarely...

$II.$ Phối hợp về thì
                  MĐC                                     MĐTG
$1.$  Các thì hiện tại                        - Các thì hiện tại
ex: I often read newspaper when I am waiting for a bus
                                                 while
      I've found out when he come back.
$2.$ Các thì QK (QKĐ)                    - Các thì QK
                                                                  (QKTD, QKHT)
ex: I had no sooner gone out than she came back.
$3.$ Các thì tương lai                      - Hiện tại
ex: I'll go home as soon as I've finished my work.
       We'll be having lunch when you arrive at  $11:30$  tomorrow.
       We'll have lived in this city for  $20$  years by the time you move to NY.
       Mary's leaving for London as soon as you come.
       When I am cooking dinner, my mother'll have finished her work in the garden.
       When I've been working for this company for  $30$  years, I'll retired.
Note: MĐC có thể làm câu mệnh lệnh hoặc câu yêu cầu.
ex: Can you wait for me until I've finished my work?