My experience is that it gets hard when they realise that they can get away with only German. Many kids choose to only use the "primary" language, even when spoken in the secondary one. They eventually regret that choice when they get to their twenties.
Not all kids do that though. I am not sure what influences this, but as a parent of trilingual children, my recommendation is to expose them to the culture as much as you can. Talk to family online, take them to English speaking places and countries, watch movies. In other words, make speaking English useful to them. If your family in the US have older kids, yours might end up looking up to them - mine have an older cousin who is one of their favourite members of the family and definitely gives motivation to communicate. Also, be more stubborn than them if they try to only speak German.
Sorry if this comes across as unsolicited advice. Nothing I said is revolutionary and you might already have thought it through. We got very lucky with ours, but this is stuff I would have benefitted from when our kids were young, so I'm passing it on.
I think that's the main thing. I have been very stubborn in "not understanding" the other (local) language with my children, even if it's obvious to them I do understand it. Today (they are still young) they speak both languages, including between themselves, and they don't seem to have a preference for one language over the other.
After a few years living in Germany (as a native English speaker), my English and that of my friends became peppered with these German-isms.
That said, after centuries of relative stability, modern Dutch is absorbing English words as fast as it can, who knows if it is still recognisable in 50 years.
Learn your languages before spreading unwise nonsense on the internet.
There's no reason to be so disrespectful.
“Ich bin seit zwei Tagen hier.”
I wouldn't be surprised if it were most languages really, English 'for' seems the weirder construction.
You could get away with it in speech since it sounds like 'since.. [thinking] two days ago' and it's acceptable to change construction like that in casual speech, but written it doesn't seem right to me.
Interestingly, I'm not sure if it's nationwide, or a local dialect (Dorset/West country) thing - interesting because there's a lot of German/Saxonism retained in the dialect, usually about word choice or spelling though, not phrases. As far as I'm aware anyway, not an expert.
(For example we tend to prefer the -t ending of -ed verbs: 'burnt' not 'burned' etc. including in stronger cases words like 'turnt' ('turned' in any usage, not the modern slang for drunk) that Wiktionary etc. will tell you are obsolete.)
But my word choices and pronunciations are definitely not 100% native. There are moments where I can feel the vtable pointing me to the wrong language for a word. Sometimes I get back to English, sometimes I pause, and sometimes a word from some other language pops out.
As an example I sometimes say “no thank you” in Swedish in situations where that is wildly wrong. I can’t speak Swedish, but I have those basic phrases in there.
Thankfully hearing it regularly keeps me up to date, though there are those moments where right in the middle of a conversation I have to stop and reflect on how exactly something is named.
After living in Germany for nearly 10 years, but working in Switzerland, my wife recently had an identity crisis because a Swiss colleague thought she was German, and had just learned Swiss German very well.
My daughter however speaks fluent English and German so I don’t think they’ll have the same problems.
Some are foreigners, others are extreme nerds who have failed to interact with people and have lived on the internet.
It's really sad.
And I would add that I think becoming more than proficient in and deepening understanding of one's own language (Swedish in that case) is important, in parallel with learning foreign languages.
My children are 6 and 9 and we've raised them tri-lingual. They mostly sound native in all three, but their Serbo-Croatian and English have some German artifacts as well. Also their vocabulary isn't quite at the age-appropriate level in English since I'm basically the only person they regularly use it with, and if I don't use a word with them, they probably don't know it. This may start to change now that my oldest has also begun reading books in English. (That went surprisingly quickly; once he started with English classes in the third grade, within 3-6 months, he no longer had a definite preference for books in German over English.)
The trap to be careful of is if your family language is German that the kids eventually stop answering in their parent's language. This seems to be easier when three distinct languages are in play, possibly. Since I speak English with their mom (Serbian), they're less pull towards the "outside" language (German). Oddly, the language the speak with each other has remained Serbo-Croatian. I'd always expected that to eventually change to German, but seems unlikely at their current ages. We mostly attribute this to them having sometimes spent several weeks alone with their grandparents in Serbia when they were young, and that being the only time they only spoke a single language for up to a month, and that having solidified it as their preferred language.
Tangentially related, I see more and more kids developing a "TV Accent" in Spanish in their early years which eventually gets replaced with their local one I'm guessing based on their exposure to parents and media vs School/Parents/Every day life
We're raising our kid to be bilingual (my husband is German), but I wonder how truly "native" my kid's English will be with me as his main source of it.