Quote
In early drafts of the script, R2-D2 could speak standard English, and had a rather foul vocabulary. Although all of Artoo's English speech was removed, many of C-3PO's reactions to it were left in.
http://www.imdb.com/...t0076759/trivia
I'm guessing that a 'special edition' of Star Wars with R2's lines being subtitled with some smart-ass comments and quips is long overdue.