THE PRESENT CONTINUOUS TENSE

AFFIRMATIVE NEGATIVE INTERROGATIVE
I am reading I am not reading Am I reading?
He is reading He is not (isn't) reading Is he reading?
She is reading She is not (isn't) reading Is she reading?
It is reading It is not (isn't) work Is it reading?
We are reading We are not (aren't) reading Are we reading?
You are reading You are not (aren't) reading Are you reading?
They are reading They are not (aren't) reading Are they reading?
    Example:
    Today they are having an excursion to our city.
    Today they are not (aren't) having an excursion to our city.
    Are they having an excursion to our city today?