Critical Second Language Period
All about this hypothesis
The Best Age??
There's a certain window in which second language acquisition skills are at their peak. Researchers disagree over just how long that window is, some say that it ends by age 6 or 7, while others say that it extends all the way through puberty while others disagree with the theory itself!
More About this Theory
After that period is over, some say it becomes much harder for a person to learn a new language. It's not impossible, but children in that critical period have the best success at achieving their goals.
Best time to learn the new language
Because children are so much more skilled at picking up a second language than adults, preschools and elementary schools are a popular choice for young children, but if you are about 13 or 14 you may wanna try to take a Spanish class or whatever language your learning
I'm a adult where did my language abilities go?
As a adult your ability to learn a new language isn't taken away from you when you turn 17 or 18 it diminishes over time therefore when your "critical period" is over your skills have become dormant. It still doesn't mean you can't learn a new language it just means its gonna be a little harder.
So should I teach my child to speak 3 languages?
Well yes and no, its rest on a sole person to decide if they want there child to learn 1,2,or 3 language's. Many parents see the critical period as a opportunity to teach the child the mothers native tongue.