The zero infinitive

The zero infinitive is used:
a. after most auxiliaries (e.g. must, can, should, may, might)
b. after verbs of perception, (e.g. see, hear, feel) with the pattern verb + object + zero infinitive
c. after the verbs 'make' and 'let', with the pattern make/let + object + zero infinitive
d. after the expression 'had better'
e. after the expression 'would rather' when referring to the speaker's own actions
Examples:
After auxiliaries:
She can't speak to you.
He should give her some money.
Shall I talk to him?
Would you like a cup of coffee?
I might stay another night in the hotel.
They must leave before 10.00 a.m.

After verbs of perception:
He saw her fall from the cliff.
We heard them close the door.
They saw us walk toward the lake.
She felt the spider crawl up her leg.

After the verbs 'make' and 'let':
Her parents let her stay out late.
Let's go to the cinema tonight.
You made me love you.
Don't make me study that boring grammar book!

NOTICE that the 'to-infinitive' is used when 'make' is in the passive voice:
I am made to sweep the floor every day.
She was made to eat fish even though she hated it.

After 'had better':
We had better take some warm clothing.She had better ask him not to come.You'd better not smile at a crocodile!We had better reserve a room in the hotel.You'd better give me your address.They had better work harder on their grammar!

After 'would rather':

I would rather visit Rome.
She would rather live in Italy.
Would you rather eat steak or fish?
He would rather work in a bank.
I'd rather be a forest than a tree.