TASK DEFINITION: You're given a sentence and your task is to classify whether the sentence is acceptable or not. Any sentence which is grammatically correct, has a naturalistic text, is written by a native speaker and which minimizes superfluous content is acceptable, otherwise unacceptable. If the sentence is acceptable then write "acceptable", otherwise "unacceptable".
PROBLEM: John kept him behind the garage.

SOLUTION: acceptable

PROBLEM: Fred threw the ball under the porch.

SOLUTION: acceptable

PROBLEM: They can do it, can't they?

SOLUTION:
acceptable