Identify the comma rule that the following sentence breaks:
In their homeroom classes, students learned of a new very strict rule that would affect their parking privileges.
A) Use a comma to separate three or more items in a series.
B) Use a comma to set off a phrase or clause at the beginning of a sentence.
C) Use a comma to separate coordinate adjectives.
D) Use a comma to set off a parenthetical element in the sentence.
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga.
Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus.
Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
I use the process of elimination on this one. We know it is not A) because there is no list or series in the sentence (apples, oranges, and carrots). It isn't D) because there is no statement within parenthesis or any kind of quoted text.
It could be B), so an easy way to check is to move the words before that first comma to the end of the sentence and re-read it to make sure it still makes sense. "Students learned of a new very strict rule that would affect their parking privileges in their homeroom classes."
That sentence still makes sense to me, so then it must be C). The adjectives we're looking at are "new" and "very" (or "very strict"). They are coordinating adjectives because they build on top of each other to describe "rule". It's not only a very strict rule, but also a new, very strict rule.
"In their homeroom classes, students learned of a new, very strict rule that would affect their parking privileges."