Since we've moved to Zürich, I don't have much opportunity anymore to speak French. My husband speaks to the kids in French most of the time, but they often respond to him in English. (And we're all learning German in school.) Naturally, I've tried to increase the amount of French I/we speak at home, but it's an uphill battle.
Just the other day, a colleague stated that if you put your kids in a situation where they have to learn too many languages (and don't follow careful rules about it), then the kids will never learn language correctly, and will spend their lives speaking some sort of pidgin. I'm very leery of such ideas. Kids are programmed to learn language without any special instruction. As long as they have a reasonable amount of human social interaction, they'll learn to use language correctly. So I don't agree that it's critical (for their development) to strictly follow the rule that I always speak to the kids in English and my husband in French.
That said -- even if I want to break that rule -- my eight-year-old son Nico is quite intent on enforcing it. (Leo is less picky, and is OK with speaking to me in French, even though he prefers English.) Nico complains whenever I speak to him in French. And the other day, he gave me an intriguing explanation of why:
"It's like you're not my mom -- it's like you're a different person." [when I speak French]
It's interesting. It seems like kids sometimes have a strict mental sorting of which person goes with which language.
Nico is willing to switch languages occasionally, though, if we're specifically making a game of it -- playing school or something.
Out of the blue, on the bus on the way to school, Nico said to me, "I understand why you don't want speak English all the time. It's because it's so ordinary and boring to just speak English."
"Yes, exactly," I said.
So Nico then devised a game where we'd speak French for a week and then German for a week and the English for a week (and came up for an elaborate point system for what to do if you use the wrong language). Since French was first, we discussed all the rules in French. It was fun!
By that afternoon, he'd forgotten about the game, and I didn't bother to remind him.
If the kids want to speak to me in French, fine. If not, that's OK. For my own sake, I just signed up to take yoga in French. :D