Problem: Produce a sentence that would be considered grammatically acceptable

Answer: I am frightened of tigers.

Problem: Produce a sentence that would be considered grammatically unacceptable

Answer: Will put a picture of Bill on your desk before tomorrow, this girl in the red coat will put a picture of Bill on your desk before tomorrow.

Problem: Produce a sentence that would be considered grammatically acceptable

Answer:
Hasn't Henri studied for his exam?