Growing up, my language was usually squeeky clean, as my Mom and Step-dad were very conservative, fundamental types, and a slip-up of the linguistic type would have been very, very bad. Now, I strive to have as full, diverse, and unincumbered of a vocabulary as possible...so of course I can't limit myself by excluding four-letter words. I control (to a degree) where and when I swear, but for the most part I have no problem peppering occasional choice words, and when things REALLY hit the fan I can let loose with the best of them. That being said, I still try (even as an adult) to never swear in front of my mother or others I know would be offended. Heck, I just started cussing in front of my dad, and he's been dropping obscenities in my presence since I was a little kid!