TASK DEFINITION: Given a sentence, generate a new sentence by performing small changes on the sentence. Here, make sure that the changes are semantically related and syntactically similar to the input. And the generated sentence should have high commonsense plausibility, that is to have reasonable probability of it being true.
PROBLEM: You are likely to find a pin in a tree .

SOLUTION: You are likely to find a grape in a tree.

PROBLEM: If you want to have a party then you should buy snacks and drinks.

SOLUTION: If you want to have a party then you should buy fish and drinks .

PROBLEM: You are likely to retrieve a piece of paper in your pocket .

SOLUTION:
You are likely to brand a piece of paper in your pocket .