Ann was playing the flute at 3 o'clock yesterday, and her brothers were playing the violin.
While Fred was switching on the vacuum cleaner, his wife was switching on the washing machine.
While I was buying vegetables, I was talking with the greengrocer.
My dad was repairing the central heating (system) at seven o'clock yesterday.
Who was playing tennis when we entered the gym?
Little Tom was looking at Europe's map (at the map of Europe), when his sister was telling him about England.
What were you doing, when Granny was making pancakes?
While the children were listening to the music, their parents were watching (observing) the sunrise.