The suffix -ing has four different uses in English:

1) Continuous tenses:

Present continuous: I am walking
Past continuous: I was walking
Future continuous: I will be walking
Present perfect continuous: I have been walking
Past perfect continuous: I had been walking
Future perfect continuous: I will have been walking

2) As the noun form of a verb. For example, in Spanish, when people put up signs saying people aren't allowed to smoke, no fumar is written. But in English they say, no smoking.

Walking is good for your health.
Smoking is bad for your health.
Stop talking please, we are watching a movie.

3) The future form: I am going to the beach tomorrow.

4) Active adjective: The movie was interesting.

Practice

1) I like Kyle because he excites me, I think he's __________.

2) If you like to ski we should go __________ tomorrow.

3) The history of Chili amazes me, I think it is so __________.

4) Tomorrow at this time you ______________ (fly) to Spain.

5) Be quiet please, the baby ___________ (sleep)

6) Do you like to bake cookies? If you do you should come to my house because we ________________ cookies this afternoon.

7) Wake up Kyle, you should be working. There is no ____________ on the job.