THE PRESENT PERFECT SIMPLE TENSE

Definition: We use the present perfect to show an action which happened in the past and continue up to the present. We form the present perfect as the following:
Click here to study the use of the present perfect tense.

I. POSITIVE FORM:

Sub + have/has + V₃ + (obj)

POSITIVE	POSITIVE SHORT FORM
I have played tennis.	I've played tennis.
You have worked here for 2 years.	You've worked for 2 years.
He has written two letters.	He's written two letters.
She has walked three miles.	She's walked three miles.
It has rained a lot.	It's rained a lot.
We have travelled for two hours.	We've travelled for two hours.
They have studied for 5 years.	They've studied for 5 years.

The negative is really simple too. Just put 'not' after 'have' or 'has':

II. NEGATIVE FORM:

Sub + have/has +not+ V₃ + (obj)

NEGATIVE	NEGATIVE SHORT FORM
I have not eaten breakfast today.	I haven't eaten breakfast today.
You have not been to Asia.	You haven't been to Asia.
He has not seen the new film.	He hasn't seen the new film.
She has not played tennis.	She hasn't played tennis.
It has not snowed this winter.	It hasn't snowed this winter.
We have not slept all night.	We haven't slept all night.
They have not tried the food.	They haven't tried the food.

To make a question, put 'have' or 'has' in front of the subject:

I. QUESTION FORMS

        A. Yes/No Question

Have/Has + Sub +V₃ + (obj)?

'YES / NO' QUESTIONS

Have I missed the bus?

Have you visited London?

Has he worked as a waiter before?

Has she met John?

Has it been cold this week?

Have we arrived too early?

Have they studied English grammar before?

As you can imagine, for 'wh' questions, we just put the question word before 'have' or 'has':

Wh-word + has/have + sub + V₃ + (obj)?

'WH' QUESTIONS

Where have I left my umbrella?

What have you done today?

Why has he gone already?

Where has she been in the UK?

Why has it rained so much this summer?

What have we done?

Where have they learned English before?