My third grader came home from school a few weeks ago with some really, really bad language--the S-word and the F-word with all its variations. It finally subsided after a couple of weeks--like it just had to run its course, despite my many varied attempts to nip it in the bud---but he has still been expressing some intense negative emotions.
I remember when my oldest was in third grade, he also became negative, sullen, and argumentative. I even wrote a long post about it here and got a lot of good advice. It culminated in our taking him out of school at the beginning of fourth grade. He's much more pleasant now.
Is this common in third-graders?