`1.` We haven't eaten out since mom's birthday.

`-` HTHT `=>` DH : since

`2.` Have you ever been to Russia?

`-` HTHT `=>` ever

`3.` She hasn't met kids since Christmas.

`-` HTHT `=>` since

`4.` Have they repaired the lamps yet?

`-` HTHT `=>` yet

Áp dụng :

`( + )` S + have/has + PII

`( - )` S + have/has-not + PII

`( ? )` Have/has + S + PII?

`- -- - - - - - -`

$\text{@Tnhye@}$

`1.` We haven't eaten outs since our mom's birthday

`2.` Have you ever been to Russia?

`3.` She hasn't met any kids since Christmas

`4.` Have they repaired the lamps yet?

Giải thích :

`-` Thì hiện tại hoàn thành 

`(+)` S + have/has + V3/ed

`(-)` S + have/has + not + V3/ed

`(?)` (W/h) + Have/Has + S + V3/ed

`-` Dấu hiệu : since , ever , since , yet