When is it okay to correct someone’s grammar? A listener from Madison, Wisconsin, says a friend went for a parent-teacher conference only to notice that a sign in the classroom read “Things your thankful for.” Should the teacher be called out? Is she committing educational malpractice by indoctrinating the four-year-olds with harmful misspelling? Before rushing to judgment, remember that teachers have an enormous amount of work to deal with, and you sure don’t want to be “that parent”! But of course, if you’re going to confront someone about a mistake, it’s always best to do it one on one. This is part of a complete episode.