$\text{1.}$ was having
$\text{→}$ When/ While + QKD/ QKTD, QKTD/ QKD
$\text{2.}$ saw - were you doing?
$\text{3.}$ saw - stopped
$\text{4.}$ told - spent - listened
$\text{5.}$ waked - went - bought
$\text{6.}$ was watering - began
$\text{7.}$ was walking - said - thought - was trying
$\text{→}$ at 3 a.m là tg xác định ở QK, dùng QKTD
$\text{8.}$ did you lend - was still reading
$\text{→}$ Tại sao bạn lại cho anh ấy mượn cuốn sách? Tôi vẫn đang đọc nó.
$\text{9.}$ were your parents
$\text{→}$ last week dùng QKD
