`1.` How long does the documentary last?

`-` forty-five minutes chỉ khoảng thời gian `->` How long

`-` Cấu trúc: How long + do/ does + S + V...?

`-` the documentary là số ít `->` does

`2.` How often does she go to the supermarket?

`->` on Sundays chỉ tần suất `->` How often

`-` Cấu trúc: How often + do/ does + S + V..?

`-` she là số ít `->` does

$\mathscr{R A C I N G B O Y}$

1. The documentary lasts forty-five minutes.

⇒  How long does the documentary last ? 

→ cấu trúc câu : How long + do/does/did + S + V ?

2. She often goes to the supermarket on Sundays.

⇒ How often does she go to the supermakert ? 

→ Cấu trúc câu : How often + trợ động từ + S + V +….