In this task, you're given a pair of sentences, sentence 1 and sentence 2, that agree with each other. Your job is to alter sentence 2 so that the pair contradict each other. Generated sentences must be short, with less than 15 words. New information can be introduced. Avoid using pronouns to confuse the subject of the sentence.

Sentence 1: Several men working on a motorcycle. Sentence 2: Several people with a motorcycle.
Two motorcycles sit in the corner of a shop.

Sentence 1: A little boy is jumping into the kiddie pool in the backyard. Sentence 2: A boy is playing in the pool.
A boy is playing in the sandbox.

Sentence 1: Three men, each wearing a white shirt and orange shorts, build a sand castle while another man, wearing the same clothing, looks on. Sentence 2: The group is building a sandcastle, while one watches.

An alien space ship resides on the beach.