Final answer:
A present active participle is a form of a verb ending in -ing used as an adjective or adverb and indicates an action being performed by the subject concurrently with the main verb. Active voice implies the subject of the sentence performs the action. Present active participles can be a part of participial phrases, which can move around in the sentence.
Step-by-step explanation:
To recognize a present active participle, look for verbs that are being used as adjectives or adverbs while showing an action that is happening concurrently with the main verb and is performed by the subject. These participles typically end in -ing. For example, in the sentence 'Skipping along the forested path, the dwarfs whistled in a merry chorus,' the phrase 'Skipping along the forested path' contains a present active participle that modifies the subject 'the dwarfs' and shows an action they are actively doing.
Unlike passive voice, where the subject is acted upon, the present active participle shows that the subject is doing the action. Consider this: 'The sloth carried her baby on her back' is in active voice because the subject, 'the sloth,' is acting for carrying, whereas in passive voice it may be phrased as 'The baby was carried on the sloth's back,' where 'the baby,' now the subject, is receiving the action.
A participial phrase can often be moved within a sentence to a certain extent without changing its meaning. For example, 'The kids went bounding down the stairs' can be modified to 'Bounding down the stairs, the kids went' without altering the sentence's meaning but still using the participle to modify the verb 'went'.