I have been reading a book for an hour.
Я читаю книгу час.
He has been painting a fence for twenty minutes.
Он красит забор 20 минут.
We have been waiting for him since morning.
Мы ждём его с утра.
She has been learning English for five years.
Она учит английский язык пять лет.
You have been cooking since 12 o'clock.
Вы готовите с 12 часов.