Olivia There is no horrible profanity in the first three books, they're all pretty good (my middle school has books 1-4 in the library, if that helps). But in the fourth book and onward, I'd be a little careful.
Olivia Wegner This question is asking about the types of swears used in the series, not the language it was originally printed in. There are very minimal swears in the first two books, with only about two in each. They're not the f-word, either. I'm not sure about the rest of the series -I haven't read them yet- but there are only a few per book for the first two.