Present Continuous

Here are some uses for the Present Continuous:

USE 1 - Now

Use the Present Continuous to express the idea that something is or is not happening now, at this very moment.

Examples:

• You are not swimming now.
• Are you sleeping at the moment?
• They are reading their books.
• What are you doing?

USE 2 - Longer Actions in Progress

We also use the Present Continuous to say that we are in the process of doing a longer action which is in progress.

Examples:

• I am studying to become a doctor.
• I am reading the book Tom Sawyer.
• Are you working on any special projects at work?

USE 3 - Near Future

Sometimes, speakers use the Present Continuous to indicate that something will or will not happen in the near future.

Examples:

• I am meeting some friends after work.
• Is he visiting his parents next weekend?
• Isn't he coming with us tonight?

USE 4 - Repetition and Irritation with "Always"

The Present Continuous with words such as "always" or "constantly" expresses the idea that something irritating often happens.

Examples:

• She is always coming to class late.
• He is constantly talking. I wish he would shut up.
• I don't like them because they are always complaining.

Source:  http://www.englishpage.com/