apostrophes and semicolons

I'm going to add this to my syllabus next term: "If you don't know how to use 'em, don't."

(Guess what I'm doing this afternoon.)

Some of my students punctuate the way Bob Ross painted. "Let's put a friendly little semicolon in that sentence." "Maybe there's a happy little apostrophe that lives here!"

They get commas right almost half the time. Periods, even more. Dashes are a problem for many, as they don't understand that hyphens and dashes are not the same thing. But a 1-en hyphen for a 1-m dash doesn't bother me, not much at all.

Misused apostrophes and semicolons, however, bug me.

OK, I feel better now. Back to the paper's.