-Occasional, but explicit cursing, not very often, and only in an expression of anger (not usually used to describe others or anything, mostly just as exclamations). Also some rare other instances, such as the following example:
Example: An angry man enters & is asked who he is, and he replies to Sheldon with "I'm the F**cking guy whose f**cking store you're in", or something along those lines. There is significantly less cursing than in most other HBO shows, especially things with the "mature" rating. I rarely if ever hear it in this show, surprisingly. There are some moments they may talk about sex, but not in a very profane or nasty way. It's more like your average show with the odd curse here & there. Maybe about once or twice an episode.
There are also a few scenes involving some bullying of highschool kids, where they call a girl "lebso" (which was supposed to be a dyslexic girl calling her a lesbo) & continually talk crap about her being a lesbian & that her mom being gay was genetic & that she was gay because of it as well.