We have a French au pair. Last year we had a French au pair. Next year we will have a French au pair. We are also lucky enough to have a house in France where the kids spend all summer. As a consequence of this my son has an awesome grasp of french.
He can say bonjour, pain au chocolat and Disneyland Paris.
He’s an idiot.
But: he also has a half Japanese girlfriend (he’s 6, they are just good friends…) and now he’s come home speaking entire Japanese sentences, and criticising my accent when I try to copy him.
Clearly the lesson here is that when you want to do something and you are in love, you can pretty much do anything you put your mind to.