The present simple is used to talk about actions we see as long term or permanent. It is very common and very important.
In these examples, we are talking about regular actions or events.
- I drive to work every day.
- She doesn't come very often.
- The games usually start at 8.00 in the evening.
- What do you usually have for breakfast?
In these examples, we are talking about facts.
- Water freezes at 0° C or 32° F.
- I have three children.
- What does this word mean?
- I don't have any of my original teeth left.
In these examples, we are talking about future facts, usually found in a timetable or a chart.
- The plane leaves at 5.00 tomorrow morning.
- Christmas Day falls on a Sunday this year.
- Ramadan doesn't begin for another 2 weeks.
- Does the class begin this week or next?
In these examples, we are talking about our thoughts and feelings at the time of speaking. Notice that, although these feelings can be short-term, we use the present simple and not the present continuous.
- I think you are wrong.
- She doesn't want to do it.
- They don't agree with us.
- Do you understand what I am trying to say.