1. Modal verbs are used to express ability, permission, advice, necessity, prohibition, possibility, and to ask questions politely. 2. They don't use the third person singular 's' or auxiliary verbs like do/does/did. 3. Common modal verbs include can, could, may, might, must, should, ought to, and have to.

1. The main characteristics of modal verbs are these ones:
1. They don’t use the third person singular ‘s’
She speak Germancan
2. After a modal verb, infinitive without ‘to’ is used
4. Modal verbs are used to express:
ability
can
could
in present time
in the past
permission
may
can
to ask for
permission
advice should to give a piece of
advice or a tip
necessity
must
have to
to say something
has to be done
rules must
to state something
is compulsory
prohibition mustn’t
to state that
something can’t
be done
not
necessary
don’t
have to
to express that
something is not
necessary
possibility
may
might
to say something is
likely to happen
to say something is
less likely to happen
polite
questions
may
could
would
to ask for
something
politely
3. They don’t use the auxiliary do, does, did
for interrogative and negative sentences
I help you?May
You take an umbrella if you’re going to Londonshould
You park here. It’s only for disabled people usemustn’t
exception: have to is a semi modal verb, it uses the auxiliary do, does, did Do I wake up early on Sundays?have to
For the third person singular is usedhas to She work tomorrowhas to

2. Examples:
ability
can
could
in present time
in the past
I can play the piano, but I can’t play the guitar
I could count to 100 when I was 5
permission
may
can
to ask for permission May/Can I use the phone?
You may/can use the phone anytime (may sounds more polite than can)
advice should to give a piece of advice or a tip You should do your homework every day
necessity
rules
must
have to
to say something has to be done
I must finish the project tonight (for myself, moral obligation)
He has to finish the project tonight (for the rest of people, here
you can use must too)
must to state something is compulsory All drivers must have a driver’s license
prohibition mustn’t to state that something can’t be done You mustn’t drive if you are drunk
not
necessary
don’t
have to
to express that something is not necessary You don’t have to come to school next Saturday
possibility
may
might
to say something is likely to happen
to say something is less likely to happen
It may rain tomorrow (here can is used too)
It might rain tomorrow
polite
questions
may
could
would
to ask for something politely
May I borrow your pen?
Could/Would you close the door, please?