The train arrives at the station at 9 AM.
Water boils at 100 degrees Celsius.
We have dinner together every Friday.
The Earth revolves around the sun.
To describe habitual actions, routines, schedules, facts, and general truths.
Positive: Subject + base form of the verb
(e.g., I read books.)
Negative: Subject + do/does + not + base form of the verb
(e.g., I do not read books)
Questions: Do/does + subject + base form of the verb?
(e.g., Do I play guitar?)
When is the -s added after the verb?