$\text{1.}$ saw - was wearing
$\text{→}$ When/ While + QKD/ QKTD, QKD/ QKTD
$\text{2.}$ started
$\text{→}$ last week chia QKD
$\text{3.}$ was cooking
$\text{→}$ At that time là tg xác định ở QK chia QKTD
$\text{4.}$ was making - went - had
$\text{5.}$ phoned - returned
$\text{6.}$ left
$\text{7.}$ were listening - was preparing
$\text{8.}$ has taught
$\text{→}$ for + khoảng tg chia HTHT
$\text{9.}$ was blowing - went
$\text{10.}$ go
$\text{→}$ every day chia HTD