At this time yesterday, the boy playing computer games was asked by his English teacher.

The question we are discussing was asked by our English teacher yesterday.

The question we were discussing was asked by our English teacher yesterday.

The boy who will be sent to America next year is learning English.

The boy who will be sent to America next year is learning English.

The bridge built last year has been destroyed by the flood.

The bridge built last year has been destroyed by the flood.

After thinking for a few minutes, he answered my question.

He thought for a few minutes and then answered my question.

He answered the question I asked after thinking for a few minutes.

Seeing him, I couldn't help crying.

-I couldn't help crying at the sight of him.