Curate, connect, and discover
Aragorn: definitely says fuck, and has to catch himself and tone it down when he becomes king
Boromir: yes. "They have a fucking cave troll."
None of the hobbits do; at least, not at first. Pippin picks up swears from Boromir, and Sam will swear under duress
Gimli: swears all the time, but mainly in Khuzdul. He definitely tries to teach Khuzdul swears to Legolas
Legolas: swears very rarely, and usually in Sindarin, which sounds so pretty that it goes unnoticed. Gimli often tries to goad him into swearing
Gandalf: knows all the swears, but doesn't say them
Galadriel: used to swear when she was younger, but that was thousands of years ago, and she no longer does.
Eowyn: swears constantly. every other word.
Faramir: swore once, and still regrets it.
Gollum: doesn't know any swears, but would say them if he did.
@fadedkat