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: I sent a book to Louis.

SOLUTION: acceptable

PROBLEM: I threw the ball to Mary, but she was looking at the birds flying overhead and didn't even notice.

SOLUTION: acceptable

PROBLEM: You didn't leave, left you?

SOLUTION:
unacceptable