Problem: Produce a sentence that would be considered grammatically unacceptable

Answer: Although Mag doesn't eggplants, Sally eats cabbage.

Problem: Produce a sentence that would be considered grammatically acceptable

Answer: Alison and David soaked their feet after dinner

Problem: Produce a sentence that would be considered grammatically unacceptable

Answer:
I loaned Maggie a Swiss Army knife whose to open the padlock with corkscrew.