Final answer:
The participle in the sentence is present.
Step-by-step explanation:
The participle in the sentence "We saw Gina waiting for the bus" is present. The present participle of a verb ends in -ing. In this sentence, "waiting" is the present participle. It is used to describe the action of Gina, who was waiting for the bus. A past participle, on the other hand, is typically used to indicate a completed action in the past and usually ends in -ed or -en.
Learn more about Participles in English grammar