I (watch) a football match / the TV suddenly (go) off / WHILE
While I was watching a football match, the TV suddenly went off. / The TV suddenly went off while I was watching a football match.
My father (make) dinner / the cooker (stop) working / WHEN
My father was making dinner when the cooker stopped working.
Some workmen (dig) a hole / they (cut) the power line / WHEN
Some workmen were digging a hole when they cut the power line.