78 They just (phone)........to say that they (not come)..........back till Sunday night

79 I lost my keys when I....(walk) home

88 I...Preparing dinner at 4p.m and I......still at it when my wife........................home(start, be, come)

89 I........ an old friend in town while I....the shopping(meet, do)

90. Yesterday evening Tom ......(have) a bath when the phone....(ring). He got out of the bath and...(answer) the phone

`*` Cấu trúc thì quá khứ đơn 

`(+)` S +V (ed/ cột 2) 

`(-)`  S + didn't + V 

`(?)` Did + S + V?

`-` DHNB: ago, last,..

`*` Cấu trúc thì quá khứ tiếp diễn

`(+)` S +was/were +V-ing

`(-)`  S + was/were +not+ V-ing

`(?)` Was/were + S + V-ing?

`*` Cấu trúc thì HTHT 

`(+)` S + have/has + V-pp 

`(-)` S + haven't/hasn't + V-pp

`(?)` Have/Has + S + V-pp+...?

`-` DHNB: yet, already,..

`*`QKTD +when +QKĐ

`1` have just phoned - won't come

`2`was walking

`3` started - was - came

`4`met - was doing

`5`  was having - rang - answered