I hadn't heard that grouping, which actually makes a lot of sense. A teacher taught me a simpler rule: "It's" normally has an apostrophe, while most words don'

I hadn't heard that grouping, which actually makes a lot of sense. A teacher taught me a simpler rule: "It's" normally has an apostrophe, while most words don't. So instead of adding a apostrophe to show possession, we remove it. Basically we're toggling the apostrophe state. Or..."it's" always results in a NOT output when compared to other outputs.