No idea when I started it, but I have a little anecdote about a friend. Quiet, calm girl, a bit shy, always nice to everyone, tried to avoid conflict whenever possible. She loved to watch her boyfriend play videogames but had zero interest in trying it out herself - she always just wanted to watch and said it felt like an interactive movie to her.

Me and her boyfriend were taking turns playing FF12 and you can kinda pre-program the behaviour of the characters with "gambits" - if done right, you can just waltz up to an enemy and watch your party go ham on it without the need to manually attack. Total no-brainer. He eventually gave her the controller and said it was her turn now, and that she doens't need to worry about memorizing button inputs and the like, just walk around and have fun, it's totally easy ...

It took all of five minutes until she was cussing like a drunken sailor, totally immersed in the game, cheering on her party, insulting the monsters. One sentence in particular almost made me choke: "Ich schlag dir den Arsch voll bis du Schätze scheisst!" (we're all German BTW) which roughly translates to something like "I'll whoop your booty until you poop loot!" (assonance included).

They're married now. ;)

I didn't until I was an adult.

I made very sure not to raise my own child that way, as if some words are inherently bad. It's the context that matters, not the word itself, and I made sure my kiddo learnt that instead of "swearing bad"

I would sometimes swear when I was 7. My mom cursed a lot so I picked it up young. She's one of these people that forcibly inserts fuck into a sentence as many times as humanely possible when upset. Example "clean your fucking room right fucking now or I am fucking taking the fucking Xbox.

I still don't curse, really. I started talking about 'inappropriate' topics probably in around year 9 though.

+/- 12 I think.

For me I was about 13-14, raised really religiously so the first time I said fuck I was sure I was gonna be struck down in the next 48 hrs.

Kindergarten. But my parents never really cared. I was told "know your audience" not "don't say that".

Not sure. Definitely by 11, and probably a bit younger

Around the same time, 3rd or 4th grade.

I know i cursed as a kid and did not very like it so i trained te be cursing free. That broke after like 10 to 12 jears after i got a friend that cursed a lot.
My mair reason why i did not like it was that if a mind reader exists i hope that at least i am not annoying. With the same motivation i structured how i think too, like less sentences that break halfway through.

13, you can see the transition in the journal I kept at the time

8 or 9yo I think

5th grade, in a 3-day camp with friends

Near the end of elementary school and the beginning of middle school. It also didn't help that my parents would swear often as well. I'm glad my little brother is calling out the hypocrisy.

My mother's stance was always something like "if you're going to swear, swear competently." Also a bit of "recognize the appropriate time and place for swearing. Home with family? Fine. Grandparent's church? Be nice"

I do swear but do it in too much moderation anyways for my parents to care.

I started cursing infront of my family before I started cursing infront of friends, heh.

I started at about 5th grade

When I was 6 or 7 years old.

Definitely middle school

never. cursing is cringe