برای منفی کردن فعل Be از الگوی زیر استفاده می کنیم:

Subject + (be) + not

مثال:

I am not (من نیستم)

You are not (تو نیستی)

He is not (او نیست - برای جنس مذکر)

She is not (او نیست - برای جنس مونث)

It is not (آن نیست)

We are not (ما نیستیم)

You are not (شما نیستید)

They are not (آنها نیستند)

جملات نمونه:

I am not a student. I'm a teacher.

من دانش آموز نیستم، من یک معلم هستم.

You are not a teacher. You are a student.

He is not outside. He's inside.

She is not angry. She's happy.

It is not a chair. It's an apple.

We are not students. We are a family.

You are not a family. You are students.

They are not students. They are workers.

نکته: 

می توان در حالت منفی این افعال را به صورت خلاصه و به شرح زیر استفاده کرد:

I am not : I'm not

You are not : You aren't یا You're not

He is not : He isn't یا  He's not

She is not : She isn't یا She's not

It is not : It isn't یا It's not

We are not : We aren't یا We're not

You are not : You aren't یا You're not

نکته: حالت غیر استاندارد فعل BE در بین انگلیسی زبان ها به صورت ain't با تلفظ "اِینت" استفاده می شود:

I ain't

You ain't

He ain't

She ain't

It ain't

We ain't

You ain't

They ain't

He ain't here  : (He isn't here.)

This ain't gonna work. (This isn't going to work.)