To express the idea that an action is repeated or usual. The action can be a habit, a hobby, a daily event, a scheduled event or something that often happens., • I play tennis. • She does not play tennis. • Does he play tennis?
It can also indicate the speaker believes that a fact was true before, is true now, and will be true in the future. It is also used to make generalizations about people or things., • Cats like milk. • Birds do not like milk. • Do pigs like milk? • California is in America.
To talk about scheduled events in the near future. This is most commonly done when talking about public transportation, but it can be used with other scheduled events as well., • The train leaves tonight at 6 PM. • The bus does not arrive at 11 AM, it arrives at 11 PM.
Sometimes to express the idea that an action is happening or is not happening now. This can only be done with Non-Continuous Verbs and certain Mixed Verbs., • I am here now. • She is not here now. • He needs help right now. • He does not need help now.
To express the idea that something is happening at this very moment., Examples:, •You are learning English now. •You are not swimming now. •Are you learning English now?
In English, "now" can mean: this second, today, this month, this year, and so on. Sometimes, we use the P. C. 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:, •I am studying to become a doctor. •I am reading the book Tom Sawyer. •Are you working on any special projects at work?
To indicate that something will or will not happen in the near future., Examples:, • I am meeting some friends after work. • I am not going to the party tonight. • Is he visiting his parents next weekend?
The Present Continuous with words such as "always" or "constantly" expresses the idea that something irritating or shocking often happens. Notice that the meaning is like Simple Present, but with negative emotion. Remember to put the words "always" or "constantly" between "be" and "verb+ing.", Examples:, • She is always coming to class late. • He is constantly talking. I wish he would shut up.