Certainly! Let's review the sentences with indefinite pronouns:
18. The party was great and somebody had a wonderful time.
- The use of the indefinite pronoun "somebody" is correct in this sentence. It refers to an unspecified person who had a wonderful time at the party. Therefore, the answer is Y (Yes).
19. I think we're lost because we seem to be in the middle of nowhere.
- The use of the indefinite pronoun "nowhere" is correct in this sentence. It indicates a place that is unspecified or unknown. Therefore, the answer is Y (Yes).
Both sentences use indefinite pronouns accurately, so no corrections are needed in these cases.