Very important place in communication, they are the ones responsible for expressing actions

emphasizes the negative 

I’m not late.
You aren’t late.	You’re not late.
He isn’t late.	He’s not late.
We aren’t late.	We’re not late.
They aren’t late.	They’re not late.
I wasn’t late.
You weren’t late.
He wasn’t late.
We weren’t late.
They weren’t late.

The major uses of be as an auxiliary verb are to form continuous tenses and the passive.

• 
  Continuous tenses of main verbs use the appropriate form of be, present or past, followed by the present participle (or -ing form). 
  
• 
  The passive form of a main verb uses the appropriate form of be followed by the past participle. 
  

The verb be is also used as a main verb. It is commonly found joining a subject to its complement. As a main verb, be is used to talk about:

• 
  Feelings and states. For this we use the simple tenses of the verb with a suitable adjective. 
  

I am delighted with the news but he is not happy.She was busy so she was not able to see me.

• 
  People’s behaviour. For this we use the continuous tenses of the verb with a suitable adjective. 
  

I am not being slow, I am being careful.You were being very rude to your mum when I came downstairs.

• 
  Be + the to infinitive is sometimes used to refer to future time. This is a rather formal use, which often appears in news reports. 
  

The Prime Minister is to visit Hungary in October.The Archbishop is to have talks with the Pope next month.

• 
  It + be: we use it as a subject when we are talking about time, distance, weather, or cost. In this use, be is always singular.
  

Hurry up, it’s eight thirty!Is it? I didn’t know it was so late.It’s thirty miles to Glasgow.Come and visit us. It’s not very far.It’s cold today but it isn’t wet.It’s very expensive to live in London.

• 
  There + is/are is used to talk about something existing. In this use, the form that be takes may be singular or plural, depending on the number of the noun, and be is sometimes contracted.
  

There’s a spare toothbrush in the cupboard.There was a cold wind blowing.There isn’t enough petrol for the journey.There are several petrol stations on the way, aren’t there?
To make the continuous tenses of the main verb be we have to use be twice, once as an auxiliary and once as a main verb.
You are being so annoying!I know I am being silly, but I am frightened.
The question form of clauses with the verb be in them is made by putting the appropriate form of be right in front of the subject.
Are you better now?Is he free this morning?Was he cooking dinner when you arrived?
H
ere is the to be for all the subjects in both long and short forms for affirmative sentences, and also for negative sentences with to be.
Affirmative: