Don’t send kids to private schools once they have been in public schools unless those schools are REALLY bad. I attended public school from Pre to 3rd grade then in 4th grade I went to a private school- St. Theodore’s a catholic school. In the end my education got really screwed up. The next year I went back to public school and found I was at least a year behind my schoolmates and a few skills even got worse. That followed me till around sophomore year when I finally caught up (although my math and hand writing are still bad.)
