I remember I had a friend who had a professor that taught a beginners level Spanish courses. The professor assigned everyone a prompt and they were supposed to write about a fun memory from their childhoods in spanish the required lenght was a page in half, and there were no other parameters or directions regarding the paper. So my friend gets the paper done and turns it into the professor the very next class period.

So, the next week rolls around and my friend gets their paper back from the professor and is shocked to see a zero written on the page. They look at the comments the professor made and it stated that they made a zero because they used a spanish word from an upper level spanish course.