3.- Bare infinitive:
The bare infinitive (without "to") is used in the following cases:
a.- After the auxiliary verb "Do" and the modal verbs (apart from ought to and have to):
Ex 1: She can play chess very well
Ex 2: Did you study French?
b.- After the expressions "had better", Would rather ou would sooner:
Ex: I'd rather stay here
c.- After the verbs make / let + name/pronoun:
Ex 1: She made me cry
Ex 2: I let my children play in the garden.
d.- After another infinitive + and, but, except ...
Ex : I want to have dinner and go to bed.