Câu khẳng định:
I am a teacher.
He is my friend.
They are our classmates.
---------
Câu phủ định:
I am not a teacher.
He is not my friend.
They are not our classmates.
Câu khẳng định :
- He is from America.
- I am a model.
- This is my compass.
Câu phủ định :
-He isn't from America.
- I am not a model.
- This is not a compass.