Grammar (The Present Progressive)

        The present progressive expresses an activity that is in progress( is occurring, is happening) right now. The event is in progress at the time the speaker is saying the sentence. The event began in the past, is in progress now, and will probably continue into the future.
                                           Form: am, is, are + ing.
(a) Sara can't come to the phone right now because she is taking shower.
(b) It's noon. I am eating lunch at the cafeteria right now.
(c) Ann and Bob are babies. They are crying. I can't hear them right now. Maybe they are hungry.

Forms of the present progressive.
Statement: I am working.
                   (You- We- They) are working.
                   (He- She- It) is working.
Negative: I am not working.
                 (You- We- They) are not working.
                 (He- She- It) is not working.
Question: Am I working?
                 Are (you- we- they) working?
                 Is (he- she- it) working?

Present Progressive short answers to the questions.
Question: Are you studying?
 
Short answer: Yes, I am.
                        No, I'm not.
Long answer: Yes, I am studying.
                        No, I am not studying.

Short question: Is Sana Studying?

Short answer: Yes, she is.
                        No, she's not or
                        No, she isn't.

Long answer: Yes, she is studying.
                        No, she's not studying. or
                        No, she isn't studing.

Short question: Are they studying?

Short answer: Yes, they are.
                        No, they're not. or
                        No, they aren't.

Long answer: Yes, they are studying.
                        No, they're not studying.
                        No, They aren't studying.