The present perfect tense refers to an action or state that either occurred
at an indefinite time in the past or began in the past and continued to the present time.
Structure: Subject + has/have + Past participle
Here's how to make the positive:
I have played / I've played
You have worked / You've worked
He has written / He's written
She has walked / She's walked
It has rained / It's rained
We have travelled / We've travelled
They have studied / They've studied
To make the negative, just add 'not':
I have not eaten breakfast today / I haven't eaten
You have not been to Asia / You haven't been
He has not seen the new film / He hasn't seen
She has not played tennis / She hasn't played
It has not snowed this winter / It hasn't snowed
We have not slept all night / We haven't slept
They have not tried the food / They haven't tried
To make a question, put 'have' or 'has' in front of the subject:
Here are the present perfect '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?
To make 'wh' questions just put the question word at the front:
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?
Usage:
To talk about unfinished actions or states or habits that started in the past and continue to the present.
('Since'- 2004, April 23rd, last year/'For'-2 hours, three years, six months)
I've worked here for six months.
I've known Sam since 2010.
To express an action that has recently been completed.
He has just cooked the meal.
Life experience.
I have been to Tokyo.
They have visited Paris three times.
We have never seen that film.
Time period that has not finished.
She has drunk two cups of tea today.
A finished action with a result in the present (focus on result).
I've lost my keys (so I can't get into my house).
She's hurt her leg (so she can't play tennis today).