Children of bilingual parents, or parents of two different languages, start to develop a bilingual brain in the womb. So by the time they are born, their brains are not the same as a monolingual child.
By the age of 3 of 4, kids have already acquired thousands (yes thousands) of words and complex grammars. Children in fact can speak many grammars that they were never taught! (If only learning a second language were this easy you’re thinking.) Although imitation can certainly help, in truth this podcast tells us that young children don’t learn by imitation and instead learn by where they are at in their personal development. This is why a little girl will repeatedly say “My teacher holded the baby rabbits,” no matter how many times her mother corrects and tells her that it’s “My teacher held the baby rabbits.” Eventually she will graduate to a higher level and use the irregular verbs, but until then, she is learning aspects of language by finding and recognizing patterns in the language she hears around her, rather than by simply imitating others.
This simply touches the surface of the information available related to child and language development. I encourage you to listen to this podcast if you get some time to hear it from a true expert, Jean Berko Gleason, a psycholinguist from Boston University who is credited with developing the “wug test,” a test of children’s knowledge of morphology.
Listen to Unfolding Language, Unfolding LIfe here.