One of the warnings that language learners hear is to be careful about confusing two languages. So a lot of learners don’t want to learn two closely related languages at the same time, such as French and Spanish. The reasons are pretty obvious: if they’re too similar and you’re a beginner in both, it might be easy to substitute Spanish vocabulary for French ones. But what about two somewhat unrelated languages? That’s almost never discussed as a problem.
Up until about a week ago, this was an unexpected hurdle in remembering my Polish vocabulary, especially with numbers for some reason. Any time I wanted to say a number, I had to consciously think about saying it in Polish and not in German. Mostly it was successful; a couple of times not so much (and don’t even get me started about how I really only want to do subject-object-verb word order now. I say this was unexpected because when you really look at it, German and Polish don’t have much in common. Sure you have a couple of nice loan words, and you’re already familiar with how cases work, but it really doesn’t help much from there. This is a fairly uncomfortable feeling to be constantly remembering to use Polish, and I don’t remember this being an issue when learning German.
It really makes sense that this would happen to language learners. It seems to be accepted now that your first language is located on one side of your brain, and any languages you learn after it will be on the other side (not entirely sure how this works for those who truly grow up bilingually). Even without hard evidence though, most people can think of somebody who had a stroke or a brain injury and could remember one language but not another. So it makes sense that if you start learning languages 3, 4, 5 and so on, that the other half gets confused and automatically defaults into your “first” second language.
I wonder how many people have experienced this problem, and how it affects their language learning. For me, I think this was actually a fairly large part of the reason why my Polish hadn’t progressed much, or why I never actively went beyond learning basic vocabulary until now; it was very frustrating to constantly compete with German.
There really isn’t any particular technique or trick I figured out to keep this from happening all the time. But I’ve been keeping pretty good track of my hours, and after around 90 hours of focused studying, it seems to not be as much of a problem as it was at first. So maybe for learners who experience it, it’s just another part of learning the language, and eventually it will become easier. The best thing to do for the time being is to slow down, think, and speak carefully.