We use the present simple to talk about actions we see as long term or permanent. It is a very common and very important tense.
Here, we are talking about regular actions or events.
  • They drive to the office every day.
  • She doesn't come here very often.
  • The news usually starts at 6.00 every evening.
  • Do you usually have bacon and eggs for breakfast?
Here, we are talking about facts.
  • We have two children.
  • Water freezes at 0° C or 32° F.
  • What does this expression mean?
  • The Thames flows through London.
Here, we are talking about future facts, usually found in a timetable or a chart.
  • Christmas Day falls on a Monday this year.
  • The plane leaves at 5.00 tomorrow morning.
  • Ramadan doesn't start for another 3 weeks.
  • Does the class begin at 10 or 11 this week?
Here, we are talking about our thoughts and feelings at the time of speaking. Although these feelings can be short-term, we use the present simple and not the present continuous.
  • They don't ever agree with us.
  • I think you are right.
  • She doesn't want you to do it.
  • Do you understand what I am trying to say.