Modal Verbs

What is a Modal Verb?
They are:
Can
Could
May
Might
Must
Shall
Should
Will
Would
Ought to
They are Auxiliary verbs which give additional and specific meaning to the main verb of the sentence
Modal verbs are also called
Modal Auxiliary verbs since they help other verbs

Use
They do not accept conjugation
They do not need other auxiliary verbs
John can speak English very well

Form:
There is no “s” in singular
There is no “do / does” in the question
There is no “don’t / doesn’t” in the negative
Modal verbs do not have all the tenses
Modal verbs use other verbs to complete the tenses
Can is completed with be able to
Must is completed with have to
You must come early
You had to come early yesterday

What do they express?
They can have more than one meaning depending on the situations
There are 3 categories of Modal Verbs:
Single Concept Modal: they have one meaning
Double Concept Modal: they have two meanings
Modals in past: They are used to express a situation in the past

Categories

Single Concept Modal

Double Concept Modal

Double Concept Modal

Perfect Modals
They refer to actions that happened in the past
It must have been a difficult decision
They should have invited her to their wedding
MODAL + HAVE + verb in past participle

Perfect Modals

Perfect Modals

Modals-like verbs
There are few verbs which often serve as modals too.
These are modal-like verbs. They need to be conjugated.