Is the language acquisition in this stage has a positive impact on the thier first language or nagative !!
ur opinion plz with the evidence
As it was said: the younger, the better. In very young age, you don't need to use some method for learning, just keep the kid in the target environment.
i have a research in this method so plz help me with books or articles that can helps me
A friend of mine is raised with two languages: Dutch and German (his mother is German, hie father is Dutch). When learning him how to speak, his father only spoke Dutch to him and his mother only spoke German. This way he now speaks two languages fluently.
I think you should start learning new languages as soon as possible. The younger, the better.