I was playing computer games yesterday.
I was playing computer games at 5 o'clock yesterday.
He was playing computer games from 2 till 3 yesterday.
We were playing computer games the whole evening yesterday.
What was Nick doing when you came to his place?
What were you doing when I rang you up?
I was not sleeping at 9 o'clock yesterday.
What was he doing yesterday?
He was reading a book.
What was he doing the whole evening yesterday?
He was reading a book
Was she sleeping when you came home?
My brother was not playing tennis yesterday.
He was playing tennis the day before yesterday.