I ( am writing ) an English exercise now.
I ( wrote ) an English exercise at this time yesterday.
My little sister ( is sleeping ) now.
My little sister ( was sleeping ) at this time yestarday.
My friends ( are not doing ) their homework now. They ( are playing ) volley-ball.
My friends ( did not do ) their homework at seven o'clock yesterday.
They ( were playing ) volley-ball.
Are you ( eating ) ice-cream now?
Were you ( eating ) ice-cream when I rang you up yesterday?
What isyour father ( doing ) now?
What was your father ( doing ) from eight till nine yesterday?
Why is she ( crying ) now ?
Why was she (crying ) when I saw her yesterday?
She ( was reading ) the whole evening yesterday.
She ( is not reading ) now
Now she ( is going ) to school.
What are you ( doing ) now? - I ( am drinking ) tea.
Were you ( drinking ) tea at this time yesterday? - No, I ( was not drinking ) tea at this time yesterday, I ( was eating ) a banana .