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: All oceans contains salt fish .

SOLUTION: All oceans contains salt water.

PROBLEM: You are likely to find an altar in a church.

SOLUTION: You are close to find an altar in a mirror .

PROBLEM: When an astronomer works he has a helper .

SOLUTION:
When an MBA works he has a job .