Back in the alarm days of college I used Pink Floyd - Time because the couple seconds of ticking before everything went off would send me into conniptions to prevent the calamity.
Then I found sleepyti.me and now I only use 'em when I can’t/haven’t gone to bed at the right time or really can’t risk missing a plane. Would recommend.










It’s a descriptive rule, not a prescriptive rule, and likely one snuck into the powerpoint to try and get the class thinking and laughing. Like calling the descriptions of gravity the “laws of gravity”, it describes something about the world we’ve seen, but there’s no Physics Police enforcing all matter follow the “Laws” - it’s just the term we use for a description of how things work.
A lot of advanced English classes are much more on the descriptivist side of things - observing patterns in ways we use language - than the prescriptivist approach we get in grade school where we’re just learning rote things like spellings.