DAD22, have you found any good research on language development for multilingual children? The data I have seen (we speak a language other than English at home, and DS5 and DS8 are enrolled in a Spanish immersion elementary school) often seems poorly researched, on both the "multilingualism is wonderful, it will make your child brighter" side and the "being exposed to more than one language too early will break your child's brain" side (caricaturing only slightly ;)).
I did a bit of research regarding the decision to teach my first child two languages from birth (3 if you count signing). That was years ago now. What I remember was that her initial language development could be delayed, but that ultimately the exposure was supposed to make her more creative (though not necessarily smarter). I don't know which studies I was trusting, nor if they were deservedly trustworthy.
My grandparents taught my Aunt French and English as a child, and they believe it made her stutter. They claim that when they stopped speaking French to her, that the stuttering stopped. I just googled this, and it seems there is some scientific evidence to support their claims.
My plan has been to focus on English if my daughter showed any signs of stuttering or mixing the languages. She doesn't mix or stutter at all, and she has known that "Daddy doesn't speak Chinese" for quite some time now (currently 2.75 years old). There's also a woman at her daycare that doesn't really speak any English. I think it's good to have monolingual people in her life who will give her a blank stare if she mixes the languages.
