* Cấu trúc câu gián tiếp:

- Dạng câu hỏi yes/no: S + asked + (O)/wondered/wanted to know + if/wheter + S + V(lùi thì)

- Dạng câu hỏi wh/h: S + asked + (O)/wondered/wanted to know + wh/h + S + V(lùi thì)

* Một số thì của động từ lùi thì:

- HTĐ → QKĐ

- HTTD → QKTD

- HTHT → QKHT

- HTHTTD → QKHTTD

- QKĐ → QKHT 

- QKTD → QKHTTD

- can/ will/ shall/ may/ must + V0 → could/ would/ should/ might/ had to + V0

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${1.}$ Lan asked Lien how much that dress cost.

${2.}$ Ba asked Tam how often she washed her clothes.

${3.}$ Phong asked Peter if he enjoyed reading.

${4.}$ Phong asked Thu when her father would leave Vietnam for the USA.

${5.}$ Hoa asked Lan if she liked sports.

${6.}$ She asked Lan how many people there were in her family.

${7.}$ She asked Nam if his sister and brother went to the same school.

${8.}$ Tam's friend asked him how long he would stay in England.

${9.}$ She asked her mom if there were some oranges in the fridge.

${10.}$ He asked his friend if it would rain the following morning.

${11.}$ He asked his friend how he/she went to the airport.

${12.}$ Tam asked Peter if he had gone to Hue three years before.

${13.}$ The teacher asked Lien what her hobby was.