`\text{- Cấu trúc quá khứ đơn: }`

(+ ) S+ Vpp/ed

(- ) S+ didn't+ V(inf)

(? ) Did+ S+ V(inf)?

`\text{1. }`Cấu trúc: When+ S+Vpp/ed, S+ Vpp/ed

(+)  When I was 12 years old, my mother often brought me to the school.

(- ) When I was 12 years old, my mother didn't often bring me to the school.

( ?) When I was 12 years old, did my mother often bring me to the school? 

$\text{2.}$ (DHNB quá khứ đơn: last night) 

(+) That baby cried a lot last night.

(- ) That baby didn't cry a lot last night.

( ?) Did that baby cry a lot last night?

$\text{3. }$DHNB quá khứ đơn: yesterday

(+) I put my key on the bus yesterday.

(- ) I didn't put my key on the bus yesterday.

( ?) Did you put your key on the bus yesterday? 

`\text{# Thesun}`