Study this example situation:

John is a bus driver, but now he is in bed asleep.

John is a bus driver, but now he is in bed asleep. - English Grammar - Present simple (I do)
John is a bus driver, but now he is in bed asleep.

So:

He is not driving a bus. (He is asleep.)

but He drives a bus. (He is a bus driver.)

Drive(s)/work(s)/do(es) etc. is the present simple:

Drive(s)/work(s)/do(es) etc. is the present simple. - English Grammar - Present simple (I do)We use the present simple to talk about things in general. We are not thinking only about now. We use it to say that something happens all the time or repeatedly, or that something is true in general. It is not important whether the action is happening at the time of speaking:

  • Nurses look after patients in hospitals.
Nurses look after patients in hospitals. - English Grammar - Present simple (I do)
Nurses look after patients in hospitals.

 

  • I usually drive to work.
I usually drive to work. - English Grammar - Present simple (I do)
I usually drive to work.

 

  • The earth goes round the sun.
The earth goes round the sun. - English Grammar - Present simple (I do)
The earth goes round the sun.

 

Remember that we say: he/she/it -s. Don’t forget the s:

  • I workbut He works
  • They teachbut My sister teaches

We use do/does to make questions and negative sentences:

We use do/does to make questions and negative sentences. - English Grammar - Present simple (I do)We use don’t/doesn’t to make negative sentences. - English Grammar - Present simple (I do)

  • I come from Canada. Where do you come from?
I come from Canada. Where do you come from? - English Grammar - Present simple (I do)
I come from Canada. Where do you come from?

 

  • “Would you like a cigarette?”  “No, thanks. I don’t smoke.”
“Would you like a cigarette?” “No, thinks. I don’t smoke.” - English Grammar - Present simple (I do)
“Would you like a cigarette?” “No, thanks. I don’t smoke.”

 

  • What does this word mean? (not “What means this word?”)
What does this word mean? - English Grammar - Present simple (I do)
What does this word mean?

 

  • Rice doesn’t grow in cold climates.
Rice doesn’t grow in cold climates. - English Grammar - Present simple (I do)
Rice doesn’t grow in cold climates.

 

In the following examples do is also the main verb:

  • “What do you do?” (= What’s your job?)   “I work in a shop.”
“What do you do?” “I work in a shop.” - English Grammar - Present simple (I do)
“What do you do?” “I work in a shop.”

 

  • He’s so lazy. He doesn’t do anything to help me. (not “He doesn’t anything”)
He’s so lazy. He doesn’t do anything to help me. - English Grammar - Present simple (I do)
He’s so lazy. He doesn’t do anything to help me.

 

We use the present simple when we say how often we do things:

  • I get up at 7 o’clock every morning. (not “I’m getting”)
I get up at 7 o’clock every morning. - English Grammar - Present simple (I do)
I get up at 7 o’clock every morning.

 

  • How often do you go to the dentist? (not “How often are you going?”)
How often do you go to the dentist? - English Grammar - Present simple (I do)
How often do you go to the dentist?

 

  • Jennifer doesn’t drink tea very often.
Jennifer doesn’t drink tea very often. - English Grammar - Present simple (I do)
Jennifer doesn’t drink tea very often.

 

  • In summer Alexandra usually plays tennis once or twice a week.
In summer Alexandra usually plays tennis once or twice a week. - English Grammar - Present simple (I do)
In summer Alexandra usually plays tennis once or twice a week.

 

I promise / I apologize etc.

Sometimes we do things by saying something. For example, when you promise to do something, you can say “I promise…”; when you suggest something, you can say “I suggest…”. We use the present simple (promise/suggest etc.) in sentences like this:

  • I promise I won’t be late. (not “I’m promising”)
I promise I won’t be late. - English Grammar - Present simple (I do)
I promise I won’t be late.

 

  • “What do you suggest I do?”  “I suggest that you…”
“What do you suggest I do?” “I suggest that you…” - English Grammar - Present simple (I do)
“What do you suggest I do?” “I suggest that you…”

In the same way we say: I apologize… / I advise… / I insist / I agree… / I refuse… etc.