How do we make the Present Continuous Tense?

The structure of the Present Continuous tense is:

subject + auxiliary be + main verb
conjugated in Present Simple  
am, are, is present participle

The auxiliary verb (be) is conjugated in the Present Simple: am, are, is

The main verb is invariable in present participle form: -ing

For negative sentences we insert not between the auxiliary verb and the main verb.

For question sentences, we exchange the subject and the auxiliary verb.

Look at these example sentences with the Present Continuous tense:

  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?