what is the mean by infinitives?
An infinitive is the simple or base form of verb always preceded by 'to'.
Example: to read, to drink, to dance.
She bought a book to read.
She wants to drink water.
He began to dance.
In all these sentences there are two actions happening simultaneously. Two verbs are used to describe the action completely.
"He began" is incomplete though it has a verb. "He began to dance" describes the complete action with the help of the infinitive "to dance".