No HomerS. We can have one.
Speaking as a school faculty member (not a teacher) married to an English teacher (who is a teacher) I can safely say yes they do. There are posters everywhere about proper use of apostrophes, including the old chestnut “An apostrophe doesn’t mean ‘Look out! Here comes an S.’” Not to mention other peeves:
Difference between lose and loose
to, too, or two
its and it’s
They get it right on their tests (not all, but most of them). Unfortunately all too many seem to have the philosophy that what happens in the classroom stays in the classroom.