Thì QKĐ ( CPĐ `-` CNV ) `:`

`-` CPĐ : `\text{S + didn't + V}`

`-` CNV : `\text{Did + S + V ?}`

`=>` `DHNB` `:` yesterday , ago , last , ...

`1`.

`-` He didn't send a letter to his penpal last week

`-` Did he send a letter to his penpal last week ?

`2`.

`-` She didn't teach us English last year

`-` Did she teach you English last year ?

`3`.

`-` They didn't do their homework carefully

`-` Did they do their homework carefully ?

`4`.

`-` The Robinsons didn't buy a lot of souvenirs

`-` Did the Robinsons buy a lot of souvenirs ?

`5`.

`-` Tourist didn't eat seafood at that famous restaurant

`-` Did tourist eat seafood at that famous restaurant ?

`6`.

`-` They weren't at the zoo yesterday

`-` Were they at the zoo yesterday ?

`7`.

`-` I wasn't very tired after the trip

`-` Were you very tired after the trip ?

`8`.

`-` Liz didn't buy a lot of souvenirs

`-` Did Liz buy a lot of souvenirs ?

`\text{@ TheFox}`