Use the Present Perfect Continuous.
They (not look) for him since Saturday.
George (collect) stamps since he left school.
You (ring) her up all morning?
I (study) English for 5 years.
They (not build) a house for 3 years.
Mr. Green (repair) his car for 2 days.
How long she (live) here?
She (not sing) a song all day.
How long you (read) this book?
How long you (play) basketball?
Answers & Comments
George has been collecting stamps since he left school.
Have you been ringing her up all morning?
I have been studying English for 5 years.
They haven't been building a house for 3 years.
Mr. Green have been repairing his car for 2 days.
How long has she been living here?
She haven't been singing a song all day.
How long have you been reading this book?
How long have you been playing basketball?