Approach to multiple language learning goal for a multilingual family

Question

I'm going to live in Japan with my future wife. She is L1 (first language) korean speaker but lived in Japan for over 10 years making Japanese her L2 (second language). My own L1 language is German and my L2 language is English.

Now as I'm going to be living in Japan I want/need to learn Japanese. But I'm also very interested in learning Korean. She on her side wants to learn my L1 and L2 languages by coincidence. It gets more complicated when we are going to have children. They most likely will be L1 Japanese speakers as they will grow up in Japan. English should be their L2 language. Yet I suppose it would be nice if they spoke their parents L1 languages to a degree for visiting each others families and such. I put up a table, stars show importance.

Wife                    Husband                 Children

L1 - korean             L1 - german             L1 - japanese  ****
L2 - japanese   *       L2 - english    *       L2 - (english) ***
L3 - english    ***     L3 - japanese   ***     L3 - (german)  *
L4 - german     **      L4 - korean     **      L4 - (korean)  *

As you can see there is hardly any combination. I read that you shouldn't learn/speak more than two languages at the same time as learning quality is likely to decrease.

Now I'm wondering what the best approach to this situation would be. To achieve a fluent level I'm convinced a continuous usage is nesseccary. Yet how should that work without crossing the 2-at-a-time border. Probably switching on an everyday, weekly, monthly basis wouldn't be beneficial either, wouldn't it?

I also fear 4 languages will degrade the childrens language abilities. As I heard about that back in university in lectures. Although I'm not sure this is state of the research anymore.

Are there current studies or any reading matter about this?

Answer 1

You should speak German with your children and your wife should speak Korean, as these are your native languages.

You should make sure your children pick up some language for use at school - probably Japanese or English. This can happen at daycare (if they start there young enough and if you can find one) or with friends, or at home (see below).

You should communicate with your wife in whatever language you want to and are most comfortable in. If this is Japanese or English, this takes care of the previous point. Otherwise less so.

The set-up will also improve your Korean and your wife's German, as you will get exposed to the language as the others are communicating with it. Combine this with usual study to actually learn the language. Your children will probably pick up Japanese from friends, daycare and school, and might very well prefer it to your native languages. Whether you allow them to ignore your native languages or not, this will also expose you to Japanese.

As the children get older, you can start having "language days" and explicitly speak a different language every now and then. I would not recommend this with young children, so that they do not get unnecessarily confused.

Answer 2

I think, that, first of all, you need to study language, which you'll use where you live. Because it would help you assimilate faster and help children too. Next language - English. It's obvious because it is the international language and can be used everywhere.

What about German and Korean. Yes, these languages very important to you, but useless in Japan, I guess. Also, it yours native languages and you'll never forget it.