How come Josh has stopped saying "mate", "love", and "bloke"? He had a very different manner of speaking in episodes 2, 3, and 4 than he does now.
Live in Britain, you develop a British accent. You'll notice changes in the way a lot of characters' syntax. Those who spoke Angla used far more proper syntax, which changed over time and exposure to Terran English speakers.
When I was young, I became friends with a guy who was always saying 'shuckins'. Didn't take me long to start saying it as well.
I generally am fairly open to the use of slang, but there are some words that just don't need it.
"Bullshit" is such a word. Bull or Boul is the french for fraud. I however prefer to think it came from a farmer, as Bulls really do know how to shit.
Colonal Potter on M*A*S*H yelled things like Horse hockey