The language preservation community's answer to this is usually that multilingualism is extremely possible and even common -- although some speakers of extremely powerful languages like English and Chinese might not have as much experience with it. :-)
A huge number of people around the world speak at least a local or family language as well as a "language of wider communication"; depending on their situation, they may easily be fully fluent in both. So a preservation-oriented policy or culture would encourage this kind of bilingualism. This was also the traditional view of the Esperanto movement, which wanted Esperanto to be the unique world-wide language of communication while preserving all of the existing languages through bilingualism. [Edit: A commenter below says this approach is less traditional in Esperantism than I thought.] But a similar result could be achieved with, say, English as the main world language, or with people speaking just a handful of regional languages as well as their family languages.
One challenge to bilingualism is that a lot of governments don't like it (for many different reasons), while another challenge is economic. Bilingualism is very possible, but people in various circumstances could easily stop viewing it as desirable or important, because language A will get them a job in the city and language B won't, and each language takes at least some time and effort to use and keep up with. (Or if people habitually move far away from their families, they'll have fewer opportunities to practice speaking with their families.)
Anyway, there are significant tensions here, but these possibilities don't have to be mutually exclusive as long as people continue to care about their family and local languages and have access to social situations that give them opportunities to use them. And it can even be government policy to try to preserve minority languages while also promoting bilingualism in other more widely-spoken languages.
> This was also the traditional view of the Esperanto movement, which wanted Esperanto to be the unique world-wide language of communication while preserving all of the existing languages through bilingualism
This is inaccurate. L.L. Zamenhof hoped that Esperanto – or at least something like it – would eventually replace all other languages. He didn’t care much for language diversity as we would understand it today, and he saw such differences between peoples as divisive and an obstacle to overcome.
Naturally, even with Zamenhof’s dreams, in the short term Esperanto or another international auxiliary language would only coexist with the native languages of its speakers. However, it wasn’t until the last fifty years or so that a certain segment of the Esperanto movement has begun to advertise Esperanto specifically as a way to safeguard language diversity by letting people keep their native language but have access to an international auxiliary language.
Not all Esperantists agree with this, and through such campaigns one gets the impression that World Esperanto Association and similar organizations are only trying to jump on the wider anti-globalization bandwagon in order to get more attention for Esperanto. Furthermore, Esperanto organizations take a quite schizophrenic approach: if Esperanto is supposed to be only an auxiliary language, why do so many Esperanto organizations praise the creation of original literature (and other cultural output) in Esperanto? Why isn't it encouraging people to write solely in their native language and then only translate it to Esperanto?
> This is inaccurate. L.L. Zamenhof hoped that Esperanto – or at least something like it – would eventually replace all other languages. He didn’t care much for language diversity as we would understand it today, and he saw such differences between peoples as divisive and an obstacle to overcome.
Thanks for the correction! I've heard exactly the opposite from Esperantist sources, but it's quite possible that people are sort of retroactively attributing their views to Zamenhof even if he would have felt quite differently -- which I guess isn't unusual in movements with a respected charismatic founder. Maybe this approach emerged somewhat later and people then described it as the "traditional" view of the movement. Can you suggest any sources or references that might clarify this issue?
Zamenhof's complete works have been gathered and published by a Japanese Esperantist, though I cannot recall his name at the moment – it has been many years since I did anything with Esperanto. Zamenhof's own statements are all about this kind of cultural diversity eventually falling away, and humanity being united under one language (and, in his advocacy for "Homaranismo", one religion, too).
The vast majority of Esperantists have never read more than one or two brief writings from Zamenhof himself and all they know of the Esperanto movement's goals are what later publications tell them. When Esperanto organizations have been claiming for a few decades now that they care about language diversity, it is no surprise that Esperantists tend to ascribe that belief to Zamenhof too, but it is very anachronistic.
Thanks, that's a very interesting point! I'll have to look into this a bit further further.
I've frequently read Zamenhof's famous congress speech that includes the part about "Ofte kunvenas personoj de malsamaj nacioj kaj komprenas unu la alian; sed kia grandega diferenco estas inter ilia reciproka kompreniĝado kaj la nia!" and the idea that human relations will be more equitable with an international auxiliary language... except now I don't know whether he in fact considered it "auxiliary" or merely "international". Now I'm thinking about the other interpretation in which he perhaps doesn't want other languages to survive in the long run.
Notably I guess he called Esperanto only "la internacia lingvo" at first until other people started to call it "Esperanto", and perhaps the concept of "helplingvo" largely postdates him, although apparently "auxiliary language" was used toward the end of Zamenhof's own lifetime (Wikipedia suggests maybe first by Otto Jespersen), and these terms seem to suggest supplementing other languages rather than replacing them.
A huge number of people around the world speak at least a local or family language as well as a "language of wider communication"; depending on their situation, they may easily be fully fluent in both. So a preservation-oriented policy or culture would encourage this kind of bilingualism. This was also the traditional view of the Esperanto movement, which wanted Esperanto to be the unique world-wide language of communication while preserving all of the existing languages through bilingualism. [Edit: A commenter below says this approach is less traditional in Esperantism than I thought.] But a similar result could be achieved with, say, English as the main world language, or with people speaking just a handful of regional languages as well as their family languages.
One challenge to bilingualism is that a lot of governments don't like it (for many different reasons), while another challenge is economic. Bilingualism is very possible, but people in various circumstances could easily stop viewing it as desirable or important, because language A will get them a job in the city and language B won't, and each language takes at least some time and effort to use and keep up with. (Or if people habitually move far away from their families, they'll have fewer opportunities to practice speaking with their families.)
Anyway, there are significant tensions here, but these possibilities don't have to be mutually exclusive as long as people continue to care about their family and local languages and have access to social situations that give them opportunities to use them. And it can even be government policy to try to preserve minority languages while also promoting bilingualism in other more widely-spoken languages.