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".

Ron wanted to be wearing a tuxedo to the party, but Caspar didn't know whether to be.
unacceptable

They can sing.
acceptable

John bit the apple.

acceptable