About two years ago it dawned on me that my son's mother tongue was german although his mother spoke to him primarily in english. This was a disorienting ego-check that made me step back and re-evaluate how I wanted to manage languages in our household.
We moved to Germany 3 years ago in part because we knew that the kids would not learn german in any useful way unless we did. The language of our communication seemed to be hard-wired as english no matter what tricks we tried. I was inspired by wanderlust and all the research I read about the bilingual advantage for children. However, my idea of how german would manifest on my kids' tongues was very english-centric and naive.
My daughter, who was 14 when we moved, was fluent in no time. Not only does she speak accent-free german but has an intuitive grasp of the language that I will never have although I've studied it more intensely. I spent 2 years in intensive german classes, really doing the homework and participating in class. My teachers were impressed but I doubt I will ever dream in german.
My son was not yet speaking when we moved here. Shortly after moving here, he entered a german kindergarden and spent his days immersed in the language. I should not have been surprised when german was his first language of choice. On the one hand I should have been happy. Linguists seem to agree that german is way harder than english and that the leap from german to english is easier than vice versa. On the other hand I felt a bit like a fail as a mom. Wasn't I talking to him enough? What about all those english books that I read?
I was reminded of spanish/english bilingual families where the kids responded to spanish questions in english and Mexican-American kids that could speak spanish but could not read or write it. I wanted my son to have a mother-language knowledge of english so I was afraid that in my zeal for a bilingual experience, I had in fact created a situation where my son would only really have a firm grasp of german. Therefore I embarked on a mission to do something I never thought I would have to do - teach my child english.
Fast forward 2 years later and I feel a lot better about my son's language development. While he still leads in german, he fully understands english and is truly bilingual. This has taken work and commitment. I realized that I was the only one in his life that talked to him exclusively in english. My daughter uses both english & german and my partner uses only german. I started to develop a language learning program with him that enriched our relationship and has him volunteering to speak in english. My experience with him led to me teaching english in his kindergarden.
As long as we live in Germany, I will have to be vigilant about his english-language education and create what amounts to a home school to teach and reinforce what I thought I could take for-granted.