Present Simple is used when we speak about regular actions in the present, facts and timetables.

Example:

Mary usually gets up at 7 in the morning.

The Earth goes round the Sun.

The train leaves in a half an hour.

Present Continuous Tense is used when we speak about actions happening now, actions in progress at present and annoying habits.

Example:

Sam is reading a book at the moment.

She is always losing her keys.

Present Perfect Tense is used to speak about actions that took place in the past but we see the result now

Example:

She has already done her homework.

They have recently come from their trip.

Present Perfect Continuous Tense is used to speak about actions that started in the past and are still in progress now.

Example:

They have been waiting here for an hour already.

BUT! We use Past Simple when the action is finished in the past. We know the time when it finished (yesterday, 3 days ago, last year)

Example:

Last year we went to Greece.

I had a Biology exam yesterday.

1. He's been being working on this painting for 3 months now.
2. Watercolour paints are costs pretty expensive.
3. I have just been finished my painting, and it needs time to dry.
4. After the dinner, I have went to the art store and bought some new brushes.
5. Painting is takes a lot of time if you want to master your skills.
6. My sister is always does leaving her paints and brushes all over the table!
7. A young artist has showed his paintings of dancing cats on the exhibition last month.
8. Julie has be come up with an idea of using coffee as paint for her new project.