Plural and Singular~
Singular -> He, she, it
Plural verb -> I, you
~Auxiliary verb~
- do/does (In the present simple).
- am/is/are/was/were (In the continous tenses).
- have/has (In the perfect tenses).
Example :
- Anna and Tony have been driving for hours.
- Anna has been driving for hours.
~Modal Verb~
The verb following a modal verb is never in the "S" form. It's always in the infinitive form.
- may    
- must
- could
- should
- will
Example : 
You should come.
~Indefinite Pronoun~
Usually indefinite pronoun take singular verb.
- everybody
- nobody
- anybody
- someone
Example :
Everybody wants to be loved.
~Compound Subjects~
Group nouns and relative clauses.
Example :
My mum is happy for me.
~Group Nouns~
Single nouns that are actually groups of people or things.
- club
- team
- company
- family
- class
- crowd
Example :
The team is organising the event.