In my,serbian,edition of book 7,when Harry says to Ron that he must destroy the locket,Ron says "...and than I had to put that f.....g thing back on"(or something like that;I had to translate it)
Did you noticed it????
In the English version they only swearing is bastard and bitch. The latter being said from Ron to Malfoy, and then of course we all know the famous Molly-Bellatrix showdown. Though Ron does say effing, he doesn't say the actual word.
my book says effing too. Ron's not the only one who has done that in the 5th book Uncle Vernon said "Enough effing owls" there aren't any major bad words in the books (effing is as close as it can get) the most they say is bitch, bastard, and arse and a couple characters do rude gestures