(ELI5) when babies are raised with bilingual families, are they learning it as just one jumbled language, or as two separate languages?

Question

Also would it become difficult to discern and seperate them when they join school for example, and interact with people that only speak one

In: 37

Answer 1

I have a friend who can speak the same language with two dialects and he switches between them when he talks to me vs his mother.