$\color{black}{1}$

→ Was cooking

$\color{black}{2}$

→ Were visiting

$\color{black}{3}$

→ Were having

$\color{black}{4}$

→ Was watering

______________________

S + was/were+ ving

S + wasn't / weren't + ving

Was / Were + S + ving

Sign :

At this time + last night , yesterday....

In + năm đã qua

all ( night , afternoon )

While

When

`-` Thì QKTD :

`+` KĐ : S + was / were + V-ing

`+` PĐ : S + wasn't / weren't + V-ing

`+` NV : Was / Were + S + V-ing ?

`=>` `DHNB` : at this time yesterday , this time yesterday , ...

`1`.was cooking

`2`.were visiting

`3`.were having

`4`.was watering

`\text{# TF}`