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: If you do n't fit your birthday party , you Can be thanked .

SOLUTION: If you do n't get your birthday key , you might be deceived .

PROBLEM: Most artists care to be well known for their work .

SOLUTION: Most artists want to be well written for their album .

PROBLEM: Signing a contract is for finalizing an agreement between services .

SOLUTION:
Signing a contract is for finalizing an agreement between parties.