We say that teenagers are those who are in the stage between being a child and an adult, they lack many thigs, the most important is the social area and what others think of them.
In the current society they are many distractios and more freedom from the parents to their sons where they can do things that were ot allowed before, it's surprising that we can be walking down the street and hear a kid screaming "bad words".
Is have being proved that teenagers use a short and not very expressive vocabulary, because of the lack of knowledge, usually when moms asks their childres "How was your day?" the answer is "Normal" or "Fine" because of lack of words to express, thats way people invent knew, to use them as they like best, "De Pana", "Tripeatelo", "Vacila", "Epa" are examples.
Also when we hear a very rude and empty vocabulary is believed it is for two reasons...
1. Becuase of social stuffs , usually used by mans, it make them feel more strong ad powerfull, they are "breaking the rules", this behavior is also supported by others, something that motivates the use of profeity.
2. A tag, they are word whit no meaning in the senteces..."Hey man, how are you man, all good man, i have ot heard from you man" this can be corrected with reading.
The best way to improve vocabulary in society is avoiding "bad words" especially with childrens and teaching the positive of a good vocabulary.