a, I haven’t seen my brother since he has gone to Ho Chi Minh City three years ago.

haven't

since

has gone  -> went

three years

b, Have you ever be to Paris?

Have

ever

be -> been

to Paris

c, This is the first time I ate Italian food.

is

first

ate -> have eaten

food

d, Amsterdam is one of the more peaceful cities in the world.

is

more -> most

cities

in the world

I haven’t seen my brother since he has gone to Ho Chi Minh City three years ago.

Lỗi sai: has gone

Sửa lại: went

Have you ever be to Paris?

Lỗi sai: be

Sửa lại: been

This is the first time I ate Italian food.

Lỗi sai: ate

Sửa lại: have eaten

Amsterdam is one of the more peaceful cities in the world. 

Lỗi sai: more

Sửa lại: most

Chúc học tốt!!~