How do we make the Present Continuous Tense?

The structure of the present continuous tense is:

subject	+	auxiliary verb	+	main verb
		be		base + ing

Look at these examples:

	subject	auxiliary verb		main verb
+	I	am		speaking	to you.
+	You	are		reading	this.
-	She	is	not	staying	in London.
-	We	are	not	playing	football.
?	Is	he		watching	TV?
?	Are	they		waiting	for John?