Can I just once again mention the other recent thread on the issue of bad language, also worth reading, entitled 'Schwein - very rude?':
related discussionA key point that bears repeating is that movies, TV, and pop songs are not reliable guides to everyday behavior. Not all Brazilians live for steamy love affairs, not all Indians run around singing and dancing, not all Scots shoot up on heroin, not all Chinese practice kung fu, not all Germans wear Nazi uniforms or lederhosen, and, amazingly enough, not all English speakers listen to rap music and use foul language in normal conversation. (-:
The target audience of the American entertainment industry, and its imitators worldwide, is teenage boys and young men 12-25, because this group is the most malleable (read: poor impulse control) when it comes to advertising. (Statistically speaking, that is; present company in this demographic excepted where appropriate. <g>)
Yes, guys in all-male groups do tend to use bad language among themselves when there's no one to stop them. And because boys and men tend to look to the movies or MTV for relaxation and escapism, they enjoy seeing an idealized image of themselves: powerful, grown-up, macho, and above all, free from those darn rules that make real life such a drag. Car chases and gunfights, unlimited sex, alcohol, and drugs, loud music and filthy language: all that is what being a real man is all about, right? (-;
But seriously, if your students wouldn't do those other things in public in real life, they shouldn't swear either. Few movies take place in ordinary offices and classrooms, so the 'But they all talk like that in the movies' argument is hardly relevant.
Of course there are some places in real life that are relatively free from rules. When I'm by myself at home, or among friends of my own age, sure, I might curse, depending on the circumstances. As Kathleen says, dropping a pen does not qualify, period, it's just not that dramatic. (Oh, darn. Bummer. Rats. Bother. Come back here, you dratted little ...)
If I'm suddenly in extremely sharp pain or have accidentally done something incredibly stupid -- banging my elbow hard, letting something burn on the stove, locking myself out -- then yes, very likely. But even then it would normally be 'Shit!' or 'Damn!', much less often 'Fuck!', which is the strongest word I would ever say at all.