1. I haven't seen him since last Christmas.

2. We have gone to Vung Tau several times.

3.He has already written to his parents.

4.Lien hasn't prepared her lessons yet.

5.They have just received a package from their grandfather.

6.Miss Huong has taught us English for 2 years.

7.Has she fedther dog yet?

8.We have never taken a bus to school before.

9.Next week, my uncle will come back home for Christmas.

10.My teacher is explaining the lessons but I don't understand what he is saying.

`1.` havent seen

`=>` since last Christmas là dấu hiệu của thì HTHT.

`2.` have gone

`=>` several times là dấu hiệu của thì HTHT.

`3.` has already written

`=>` already là dấu hiệu của thì HTHT.

`4.` hasn't prepared

`=>` yet là dấu hiệu của thì HTHT.

`5.` have receive

`=>` just là dấu hiệu của thì HTHT.

`6.` has taught

`=>` for 2 years là dấu hiệu của thì HTHT.

`7.` Has/feed

`8.` have never taken

`9.` will come

`=>` Next week là dấu hiệu của thì tương lai.

`10.` don't understand

$@Mon$