Grammar code switching

Hi Matthias,

Based on my experience with my own daughter, and from years of studying code-switching and other language phenomena (I'm a linguist by training), I'd say it's the normal thing to do for children who are being raised bilingually. It's like when we were growing up and learning our first language; if there were irregularities, we would make them 'regular,' regardless of how often our parents would provide the appropriate input (basically, what you mentioned you do with your son), and eventually we figured it out and began to use the appropriate tense, plural form, etc.

I'm a native speaker of Spanish who lives in the US, and I'm also trying to teach German to my daughter (she's currently 4 and a half). All of a sudden, she's begun to use 'zu' for infinitives when the sentence has a modal verb (according to German grammar, when modals are used, the main verb goes at the end of the sentence without this 'zu' particle; so instead of saying "wir müssen dieses Buch kaufen" (we must buy this book - she's pretty opinionated sometimes, ha, ha!)), she would say something like "wir müssen dieses Buch zu kaufen"). Lately she says sentences like this one, and she didn't do that before (she would say the same sentence but without the 'zu'). Same with Spanish. There are some past participles that are irregular, she used them correctly (for example,' roto,' which means 'broken' as in "he roto el juguete" - "I have broken the toy" -, and now she uses that participle with the ending of regular verbs (and it's kind of cute when she says "he rompido el juguete")...but it's part of the (bilingual) acquisition process. And she keeps saying "¿Qué es para?" in Spanish for "what is this for?" when the correct Spanish structure is "for what is this?," so as you can see, she says the Spanish sentence with the English structure (so far, it's the only English influence I've noticed in her Spanish). She'll figure it out eventually.

In fact, if you ask me, it's pretty darn smart when our kids do things like these because that means they've begun to notice grammar subtleties, and they have begun to learn them. My daughter has figured out that you need an infinitive at the end of the sentence with modal verbs in German, and every other infinitive she hears me use has the word 'zu,' so there she goes!, using 'zu' more than she should. Your son must now realize that there are a significant amount of sentences in German that place the verb after the subject, so he's doing that because he's learning that unconsciously from the input he hears, especially if he has noticed that's the word structure in English. Word order is a more complicated cognitive concept to learn, so...it's all about trial and error for them at this stage. 

If you continue with your efforts to provide the two pillars of successful bilingual upbringing (i.e. sufficient exposure and need to use the ml, as stated in Adam's book), everything is going to be OK. As I always say, they're not making 'errors' (there's a logic to what they do): they're in the process of figuring out things, that's all.

Hope it helps!

Marisa