$*$  Thì QKĐ với động từ thường :

$(+)$ S + Ved/V2

$(-)$  S + didn't + V-bare

$(?)$  Did + S + V-bare ?

$*$  Thì QKĐ với động từ tobe :

$(+)$  S + was/were + ...

$(-)$  S + was/were + (not) + ...

$(?)$  Was/Were + S + ... ?

$3. $

$→$  My parents didn't come to visit me last july

$→$  Did your parents come to visit me last july ?

$-$  Dấu hiệu : Last july

$4. $ 

$→$ The hotel wasn't very expensive

$→$ Was the hotel very expensive ?

$5. $ 

$→$ I didn't have a bicycle when I was young

$→$ Did you have a bicycle when you were young ?

$-$  Dấu hiệu : When I was young

$6. $ 

$→$ The children didn't go to the zoo yesterday 

$→$ Did the children go to the zoo yesterday ?

$-$  Dấu hiệu : yesterday

$7. $ 

$→$  Ernie didn't eat the last doughnut

$→$  Did Ernie eat the last doughnut ?

$8. $ 

$→$  They didn't buy a new house last month

$→$  Did they buy a new house last month ?

$-$  Dấu hiệu : last month