i wanna know how different between japanese adolescent langauge and japanese adult language?

Just like in the U.S., Japanese kids are more likely to use Pop slang (i.e. ohha, instead of ohaiyo gozaimasu, etc.) and are also more likely to use the plain form of words than the -masu form. Also, even though kids will sometimes use polite (-masu) form, they almost NEVER use keigo (formal speech) and don’t really learn it until they graduate and start working. It’s really difficult to say more without getting into a lot of lengthy particulars. Just like in the U.S., the language of youth especially is constantly in flux. What might have been cool 10 years ago might not even be used at all now (e.g. how often do you use the word ‘rad’?). Japanese manga can be a good source for current slang, cuss words, and informal speech if you want some concrete examples.

There are some differences between young Japanese and adult.

Young Japanese people is more likely to use created words(informal words),like American young people ,or dirty words.

Spoken language change as time passes. Also, they are influenced by TV, actors, actress or entertainers. Also, a tone is more changeable in young people’s conversation.

In my opinion, adults use more formal words. But in pubic occasion, both of the generations try to use formal words.

If adults use informal words, they look wired. I think, sometimes words that people use represent their ages.

I hope it helps you.