I was just thinking. Swear words are considered inappropriate to use in professional situations (like teaching), so many people learning the English language aren't taught how to use them.
But, they're important words to know if you want to speak fluently! As a native speaker I can tell you that, even though it's rude to say, "fuck" is one of the most expressive and versatile words in the language. It can be used for anything from humour to anger, or just general expressiveness. If you become good friends with native speakers, I guarantee you will hear swear words at some point (unless they're elders or devoutly religious), and if you're friends with teenagers you'll hear them all the time. Having only a partial understanding of how they work could lead to some unfortunate misunderstandings.
So my question to English learners is, are you taught swear words? Do you think they're important to know? How do you learn about them?