Present Perfect
Large blocks of flats ... (appear) in the suburbs.
Large blocks of flats have appeared in the suburbs.
He ... (ride) his new bike all day.
He has been riding his new bike all day.
... you ever ... (be) up a skyscraper?
Have you ever been up a skyscraper?
It's terrible. Mary ... (have) an accident.
It's terrible. Mary has had an accident.
How long ... you ... (be) her friend?
How long have you been her friend?
She ... (work) since 7 o'clock.
She has been working since 7 o'clock.
I ... (visit) it twice.
I've visited it twice.
You ... (play) computer games since 4 o'clock.
You've been playing computer games since 4 o'clock.
He ... just ... (eat) the last piece of cake.
He has just eaten the last piece of cake.
How long ... you ... (study) English?
How long have you been studying English?
How much ... the world population ... (increase) over the last few decades?
How much has the world population increased over the last few decades?
You are so dirty! What ... you ... (do)?
You are so dirty! What have you been doing?
I ... (not see) him since last Xmas.
I haven't seen him since last Xmas.
She ... (travel) for 3 months.
She has been travelling for 3 months.
The world population ... (reach) 7700 million in 2019.
The world population reached 7700 million in 2019.
She ... (write) 2 excellent books.
She has written 2 excellent books.
... Mike ... (fly) a kite before?
Has Mike flown a kite before?
How long ... they ... (wait) for you?
How long have they been waiting for you?
Since March, the pandemic ... (start) to spread all over Colombia
Since March, the pandemic has started to spread all over Colombia
My eyes hurt. I ... (work) on the computer all day.
My eyes hurt. I've been working on the computer all day.