The Present Simple is used for:
regular actions or events
He plays tennis most weekends.
The sun rises in the east.
facts known about the future
We leave at 8.30 next Monday
thoughts and feelings about the time of speaking
I don't feel very well.
The Present Continuous is used for:
the time of speaking ('now')
Shh, I'm trying to hear what they are saying .
things which are true at the moment but not always
We're looking for a new flat.
present plans for the future
We're having dinner with them next week .
Look at these examples :
- I don't usually have cereals for breakfast but I'm having some this morning because there is nothing else.
- I often cycle to work but I'm taking the car this morning because it's raining very hard.
- I'm thinking about having my hair cut short but I don't think my husband will be very happy about it.
- My parents live in Washington but I'm just visiting.
Note how, in all these examples, we use the present continuous to talk about events which are temporary/limited in time and the present simple to talk about events which are habits/permanent.