[schoen]

The official position of modern IAL advocates like Esperantists is that everyone should be bilingual in a local or family language as well as in the world language. There is someone on HN who has pointed out (I forgot exactly when) that this is actually not the historical tradition in Esperanto, but it's extremely strong nowadays.

I guess one thing that leads to divergent attitudes about multilingualism and language planning is people's different intuitions about whether bilingualism is easy or hard. Some people feel bilingualism is literally automatic (just have children regularly spend time in different language environments), while some people feel it's expensive or prone to failure modes where some children favor one language or another, suffer cross-linguistic interference (which might not harm their intelligibility at all in their own immediate environments, but might be at odds with language planning goals), or become less than fully fluent or less than fully literate in one or more languages.

I was taught the "bilingualism is automatic" view and I know there's a lot of scientific consensus behind it, but it also seems like the fine details are complicated: not all children and not all adults will be enthusiastic about achieving and maintaining equal fluency in languages they use in different contexts, or necessarily about following a national or international standard to maximize understanding with outsiders!

My father's family (in New York) stopped speaking German in his generation, so I'm not a native German speaker, as my grandfather was. I've been sad about this, especially with the intuition that I could "easily" have been a fluent native German bilingual speaker "for free" with no adverse consequences to my English proficiency. But maybe that's not literally true (maybe my English would have been more idiosyncratic and less standard, maybe I would have lost interest in German as a child and become bad at it, maybe I would have divided my reading time between languages and ended up with a slightly smaller English vocabulary?).

[dahart]

That is a more reasonable position than trying to imagine or push a single language. And yes, acknowledging it’s not everywhere necessarily, it does seem like multilingualism is fairly automatic out of necessity in much of the world. As an American, I’m sad that the US scores so poorly on multilingualism. I’m very impressed when I travel how many people speak multiple languages. There are so many places where even entry level jobs require 2 or 3 languages.

[schoen]

Yeah, I know people's intuitions are also different there, as almost everyone I've met from Europe speaks 2-4 languages fluently and doesn't consider this exceptional. That makes multilingualism feel very attainable, because it's socially normal. From the U.S. point of view this is amazing, because it's taken for granted there, where it might be a celebrated achievement here.

What I know less about is how much time or effort that multilingualism took, whether peer pressure forced some reluctant kids to stick with languages they were otherwise less interested in, and whether there are any hidden costs.

An example could be replacement of some native vocabulary by English vocabulary (which is happening in many languages). This is a benefit for many people who work internationally, but it probably harms intergenerational understanding on some topics. For example, a Brazilian friend of mine gave a computing history lecture where he noted that Brazilians briefly used Portuguese vocabulary for computer engineering in the 1970s before it was supplanted by English loanwords. That change might mean that older speakers would understand younger speakers less well on some technical topics, or that younger speakers would have a harder time reading older technical documentation. From the point of view of monolingual Portuguese speakers, the internationalization of that vocabulary might not seem like a pure advantage.

I also know that some majority language speakers in Finland (who probably expect to speak English with non-Finnish speakers) greatly resent having to spend a lot of time studying Swedish, the "other national language", if they don't anticipate using it in their day-to-day lives.

https://en.wikipedia.org/wiki/Mandatory_Swedish

In that case, it feels to some of them like the government is requiring them to be multilingual in a specific way that isn't their own preference or that doesn't align with their existing sense of ethnolinguistic identity. It doesn't seem like it's doing any kind of long-term harm, but I guess having any mandatory school subject that you don't enjoy can be pretty unpleasant, and maybe give you a more negative experience of formal education in general.

Some of the Swedish minority there doesn't prefer a future in which Finnish speakers only speak English to them (a phenomenon that already exists and that I think is growing over time). Even though it's officially legally protected, the practical status of their local minority language is being eroded by international culture.

I also have a native Finnish-speaking friend who enjoyed learning Swedish as a foreign language as a child, and ended up moving to Sweden and becoming a university lecturer (who usually teaches in Swedish). Foreign language learning can always be a benefit to anyone of any background.

To again brainstorm trade-offs, it's possible that that outcome is a bit disagreeable to her family back in Finland (who might have preferred her to stay closer to where she grew up, which might have been more likely if she had been more monolingual).