One of the most characteristic presentations is the sudden declaration of independence or an attempt at secession. It is no longer cool to eat at the table and snacks have replaced regular meals. Her previously gorgeous clothes have become unwearable. I need some money. About the same time you notice a change in language, from English to teenspeak.
Familiar words acquire different meanings.
We can now turn to category II evidence of becoming a teenager. Although you as the parents foot the telephone bill, you now find you have to book an appointment with your child to use this object of communication. She may just have gotten off the bus from school, but as soon as she enters the house, she drops her school bag on the floor, grabs a pop and a sandwich and heads straight to her room to phone her friend Rita, whom she had just seen on the bus mere minutes before. And it comes as no surprise to anyone that the teenager's room is something to behold. Candy bar wrappers and empty bags of chips compete for space with pop cans, shoes, and discarded clothes.