Use the Present Continuous with Normal Verbs to express the idea that something is happening now, at this very moment. It can also be used to show that something is not happening now.
You are learning English now. You are not swimming now. Are you sleeping? I am sitting. I am not standing. Is he sitting or standing? They are reading their books. They are not watching television. What are you doing? Why aren't you doing your homework? USE 2 Longer Actions in Progress Now
In English, "now" can mean: this second, today, this month, this year, this century, and so on. Sometimes, we use the Present Continuous to say that we are in the process of doing a longer action which is in progress; however, we might not be doing it at this exact second.
Examples: (All of these sentences can be said while eating dinner in a restaurant.)
I am studying to become a doctor. I am not studying to become a dentist. I am reading the book Tom Sawyer. I am not reading any books right now. Are you working on any special projects at work? Aren't you teaching at the university now? USE 3 Near Future
Sometimes, speakers use the Present Continuous to indicate that something will or will not happen in the near future.