What verbs result in a “swearing mildly” action? all of my experiments failed except for darn.
Looks like you have to dig into the Standard Rules to find them, since Inform 7 is a very polite application.
At a cursory glance swearing mildly appears to be caused by the “bother”, “curses”, “drat” and “darn” commands.
Note that in the next release, both varieties of swearing will be excised - the game won’t recognise them at all. Currently, I7 games by default respond to >FUCK {NOUN} with the world’s best break-up line, ‘I only understood you as far as wanting to fuck’, so this is probably a sensible decision.
(But I wrote their obituary some time ago, and they’re still around, so, y’know.)