Definition
The Present Simple tense is used to describe:
Habitual actions: Things that happen regularly.
General truths: Facts that are always true.
Scheduled events: Timetable or scheduled events.
Rules
Affirmative: Subject + base form of the verb (+ s/es for third person singular)
Example:
I play soccer.
She plays soccer.
Negative: Subject + do/does not + base form of the verb
Example:
I do not play soccer.
He does not play soccer.