`2`called-was watching

`3`.  was calling - wasn't 

`4`. were talking - walked;

`5`.fell - was reading

`6`. were waiting - arrived

`7`.Were ... playing - started

`8`. were driving - stopped

`9`. were driving - stopped;

`10`.was studying - was having

`@` Công thức Thì quá khứ tiếp diễn :

`+` S + was/ were + V-ing (+ O)

`-` S + was/ were + not + V-ing (+ O)

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

`+`Thì quá khứ tiếp diễn được dùng khi muốn nhấn mạnh diễn biến hay quá trình của sự vật hay sự việc hoăc thời gian sự vật hay sự việc đó diễn ra

`\color{#145277}{N}\color{#246483}{a}\color{#34768F} {e}\color{#44889B}{u}\color{#539AA7}{n}`

`@` WHEN : Diễn tả `1` hành động đang xảy ra thì `1` HĐ khác xen vào

`=>` When + S + V2/ed, S + was `/` were + V_ing

`=>` While + S + was `/` were + V_ing, S + V2/ed

`@` WHILE : Diễn tả `2` hành động xảy ra song song với nhau

`=>` While +  S + was `/` were + V_ing,  S + was `/` were + V_ing

`----------`

`2.` called `-` were watching 

`3.` called `-` wasn't `-` was studying

`4.` were talking `-` walked

`5.` fell `-` was reading

`6.` were waiting `-` arrived

`7.` Were `...` playing `-` started

`-` Started + V_ing `/` to V : Bắt đầu làm gì

`8.` were driving `-` stopped

`9.`  was blowing `-` went 

`10.` was studying `-` was having