Subjects do the action.
- I
- you
- he
- she
Verbs are the action, and reflect the subject doing them and the time.
- eat, eats
- am eating, are eating (right now)
- ate, used to eat (in the past)
Infinitives are actions not matched up with a subject and not confined to a time.
- to eat
- to drink
- to run
- to walk
