Participle clauses are clauses that begin with present or past participles. Participle clauses can be used when the participle and the verb in the main clause have the same subject. Participle clauses with past participles have a passive meaning.

http://www.bbc.co.uk/learningenglish/english/course/intermediate/unit-27/session-2/activity-3

http://www.bbc.co.uk/learningenglish/english/course/towards-advanced/unit-29/session-1