You may have left your umbrella in the bus.
He may have gone to the cafe to wait for us.
It may have been Helen who rang you up.
They may have come by plane.
She may have had a very good English teacher.
It may have been too cold for the children to go out.
He may have taken his children to the zoo.
They may not have seen us in the crowd.
Robert may have used a dictionary.
Mary may have misunderstood you.
Henry may have waited for us there.
Ann may have returned very late last night.
They may have seen the new play.
Nick may have left his exercise book at home.
My parents may have gone to the Russian Museum.