[subject] + am/is/are + [verb]-ing
[subject] + am/is/are + not + [verb]-ing
am/is/are + [subject] + [verb]-ing?
The present continuous says that something is happening at the moment you speak. It has two parts: am, is or are, and the verb with -ing.
In speech and messages, use the short forms: I'm, you're, he's, she's, it's, we're, they're. In formal writing, use the full forms.
Not goes after am, is or are. In a question, am, is or are goes before the subject.
Short answers have no -ing and no short form at the end: Yes, I am. No, she isn't.
It also says that something is going on in this period, even if it isn't happening at this second.
Most verbs just add -ing: work – working. A verb ending in -e loses the e: make – making. A short verb ending in one vowel and one consonant doubles the consonant: sit – sitting, run – running.
Verbs like know, want, like and understand stay in the present simple, even about now.