Present continuous tense

The present continuous tense is sometimes called the present progressive.

Here is how to form the present continuous tense in English.

Structure of present continuous
positive negative question
I'm (I am) reading a book.  
You're (you are) reading. 
We're (we are) reading. 
They're (they are) reading. 
I'm (I am) not reading.
You're (you are) not reading.
We're (we are) not reading.
They're (they are) not reading.
Am I reading?
Are you reading?
Are we reading?
Are they reading?
He's (he is) reading a book.
She's (she is) reading a book.
It's (it is) raining.
He's not / he isn't (he is not) reading.
She's not / she isn't (she is not) reading.
It's not / it isn't (it is not) raining.
Is he reading?
Is she reading?
Is it raining?

Present continuous - common mistakes
Common mistakes Correct version Why?
They still waiting for you. They are still waiting for you. to form a continuous tense we use be + -ing.
They are still waiting for you? Are they still waiting for you? In questions the subject (they) and the auxiliary verb (be) change places.
Do they still waiting for you? Are they still waiting for you?
Where they are waiting for you? Where are they waiting for you?
She doesn't watching TV. She isn't watching TV. To form the negative we put not after the verb be (am not, is not = isn't, are not = aren't).
I'm believing you. I believe you. Some verbs are not used in continuous tenses - these are called stative verbs (e.g. believe, come from, cost, depend, exist, feel, hate, like).

test_beg4 Practise this grammar (beginner/elementary): Present continuous vs. simple exercise (1)
test_beg4 Practise this grammar (beginner/elementary): Forming questions in the present continuous