My point was not that someone has to be a college professor to understand these terms; quite the opposite. Everyone can and should. My point was that many people—for whatever reason—don’t currently know them. However, I will add to that that I have met many people who either don’t want to learn them or believe (incorrectly, in my opinion) that they can’t. My opinion about what people do and don’t know is based largely on teaching this stuff at the graduate level and polling my students on which terms they knew.
To take the most germane example, one will “never” master the use of commas without understanding the concept of restrictive vs. non-restrictive (phrases, clauses, appositives, etc.) Yet, year after year, when I would ask my students whether they knew what these terms meant, virtually no one ever did—maybe 5 or 6 out of ~400 over 10 years. So, Jan could have answered some of the questions that have arisen in this thread using those terms. She could have either left folks to go look up the terms themselves so they could understand her answer, or she could have explained them and then used them to answer the questions, hoping everyone would master the concept right away. Instead, she answered the questions using non-technical language.
Both the comma you put in and the comma you left out were the correct choices.
"When the Round Table is broken every man must follow Galahad or Mordred; middle
things are gone." C.S. Lewis
“The chief purpose of life … is to increase according to our capacity our knowledge of God by all the means we have, and to be moved by it to praise and thanks. To do as we say in the Gloria in Excelsis ... We praise you, we call you holy, we worship you, we proclaim your glory, we thank you for the greatness of your splendor.” J.R.R. Tolkien