Verb (v.)

Verb is the main part of a sentence. Each sentence contains a verb. You might have a sentence without a subject or object but not without a verb. You can have a full sentence with a verb only. Look at the examples below:

Go.
Listen.
Sit.
Come.
Stop.
Eat.
Run.

Verb contains the time of the sentence:

Went                        Go                         Will go
Past                       Present                      Future 

Verbs can be positive or negative:

Went                        Go                         Will go
Didn't go              Don't go                 Will not go
Past                       Present                      Future 

Verbs can be simple, perfect or progressive:

Go                        Gone                     Going
Simple                  Perfect                 Progressive

For more information visit http://learnenglish.britishcouncil.org/en/english-grammar