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: People often pay for a restaurant bill by using a credit card.

SOLUTION: People often switch for a restaurant bill by using a credit card .

PROBLEM: You would bake a cake because a friend was celebrating a birthday.

SOLUTION: You would bake a number because a friend was wasting a birthday .

PROBLEM: You are likely to log a gate in a fence .

SOLUTION:
You are next to find a gate in a fence .