15.1. Participle I has the same forms as the gerund.

         Participle II has only one form, e.g. played.

         15.2. a) Participle I Indefinite Active and Passive usually denotes an action simultaneous with that of the finite verb.

                   I heard you laughing.

b) Participle I Perfect Active and Passive denotes an action prior to the action expressed by the finite verb.

         Having waited an hour, the crowd were getting impatient.

c) Participle I Indefinite can denote a prior action when two short connected actions are close in time.

Opening the file, the detective took out a newspaper cutting.

              But when the first action is not short, the perfect form must be used.

                   They left the restaurant, having spent two hours over lunch.

                5.3. a) Participle II can express both an action simultaneous with, or prior to, the action expressed by the finite verb. The latter meaning is more frequent.

                   Cut above the right eye, the boxer was unable to continue.

            b) Participle II of transitive verbs has a passive meaning.

                   The terrorists used a stolen car. (= The car was stolen.)

            c) A few intransitive verbs (usually denoting passing into a new state) can be used as attributes with active meanings.

                   a fallen leaf (= a leaf has fallen)

                   vanished civilizations                       faded colours

                   a retired general                               swollen ankles

    an escaped prisoner

                               Rescuers are still working in the ruins of the collapsed hotel. 

16.