What are they doing?
- They are playing football.
Main use: action which is being done at the same moment.
Syntax: Auxiliary BE (conjugated) + Verb ending in -ING
Examples:
I am playing football.
You are playing football.
He/She/It is playing football.
We are playing football.
You are playing football.
They are playing football.
Negation: I am not playing football, you are not playing football...
Question: Am I playing football? Are you playing football? Is he playing football? ...
Answers:
Are they playing football?
Long answers: Yes, they're playing football. No, they aren't playing football.
Short answers: Yes, they are. No, they aren't.