Verbs simple aspect Continuous(progressive) aspect Perfect and Perfect Continuous aspect

Pam may tell him the news, (infinitive)
Pam may have told him the news, (perfect infinitive)
{= It is possible that Pam has told him the news.)
Present simple
FORM
I work, etc.
Do/Does + infinitive for questions, negatives and short answers
USE

• 
  A regular repeated activity.
  

We often use the present simple in this way with adverbs or adverbial phrases of frequency: sometimes, never, occasionally, every day, on Saturdays, once a week, etc:
I catch the 8 o’clock train every day.
He attends the board meeting every Monday.

• 
  Something that is generally true; a statement of fact:
  

Water boils at 100 degrees centigrade.
Cats don’t like water.
Where do you work?

• 
  With stative verbs, that is, verbs that describe sentiments, thoughts and states rather than activities: