Present Perfect
Large blocks of flat ... (appear) in the suburbs.
Large blocks of flat have appeared in the suburbs.
He ... (ride) his new bike all day.
He has been riding his new bike all day.
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 firend?
She ... (work) since 7 o'clock.
She has been working since 7 o'clock.
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?
You are so dirty! What ... you ... (do)?
You are so dirty! What have you been doing?
I ... (not see) him since last Christmas.
I haven't seen him since last Christmas.
She ... (travel) for 3 months.
She has been travelling for 3 months.
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?
My eyes hurt. I ... (work) on the computer all day.
My eyes hurt. I've been working on the computer all day.