So after reading this thread, I've been experimenting with this kind of strategy for my 26 m/o in the past few days, and I realize I have some questions for anyone who cares to answer. :)
1) What do you do about communication that is not a request? Most of the things DD says are statements about the world, like "It's a big cup!" or "Teddy is sleeping," or "Mama and (DD) are here, Papa is at work," or whatever. Normally, I instinctively reflect that stuff back to her, always in my language regardless of the language she used to say it. Am I supposed to be ignoring these statements if she doesn't say them in my language? I notice this strategy decreases her overall exposure to my language because I don't talk to her as much when I stop reflecting half of the things she says (and also she doesn't get to hear how those things are said in my language).
2) What about code-switching? Do I ignore the whole sentence if a couple of the words are in the 'wrong' language? What if half of them are? Etc.
3) What should I do when she uses DH's language? We want to reinforce that one also, my grasp of it isn't enough for me to feel comfortable speaking it back to her but I definitely understand everything she says in it. Do you think I should insist that she speak only my language to me or is either non-community language OK?
TIA for your input!
Those are really great questions. I am eager to her others' input, but here's my experience. So far, DD has been talking to me 99% in Arabic. When she says a word that she only knows in English, I get excited with her and then tell her what it's called in Arabic. After a few times, I say: "What's that in Arabic please"? And then after that she uses the Arabic. The one time where she refused, as I described above, was a request, so I just ignored it and DH responded to her.
DD does do some code-switching, but honestly, I code-switch when I talk to my English speaking Arab family members and friends too :) In those cases where she code-switches, I just reflect the sentence back fully in Arabic.
I can't help you with personal experience with question 3 because we're not in a trilingual environment which I am sure is a much bigger challenge. But if you wanted my advice I would reinforce your minority language while DH reinforces his.