$\text{1. }$Where had you taught before you came here?

- Cấu trúc: Before+ S+ V_ed/ bqt, S+ had+ V_pp

$\text{2. }$She hasn't written her grandmother yet.

- DHNB hiện tại hoàn thành: yet

- Cấu trúc: S+ have/ has+ V_pp

- Chủ ngữ "she" số ít nên dùng: has

- Phủ định thêm "not": hasn't

$\text{3. }$I had a computer when I was a child.

- Đằng sau có mệnh đề thời gian trong quá khứ ( When I...a child: Khi tôi còn là một đứa trẻ => Bây giờ "tôi" đã lớn) => Vế còn lại cũng chia quá khứ

- Cấu trúc: S+ V_ed/ bqt

- "have" sang quá khứ là: had

$\text{# themoonstarhk}$

`1.` Where had you taught before you came here?

`-` Thì QKHT: S + had + Vpp + .. 

`2.` She hasn't written to her grandmother yet.

`-` Thì HTHT - yet là DHNB, form: S + have/has + Vpp

`3.` I had a computer when I was a child.

`-` Thì QKĐ - when I was a child. là DHNB

`-` Cấu trúc: S + Ved/Vc2 + ...