There are increasing numbers of Spanish speaking communities in the US that are mostly populated by immigrant and descendant communities.

The descendants still lose their Spanish though. There's a steady influx of new immigrants that keep things going, but the pattern of first-generation=limited English, second-generation=bilingual, third-generation=English only/limited heritage language still holds.

There are 41 million Spanish speakers in the US, and I've personally seen areas in the US where the first language is Spanish, and not English. Based on that, it seems likely to me that further generations would continue to speak Spanish rather than assimilate to English language. What are you getting your assertion on?

Have you looked at the source for that 41 million Spanish speakers? It's available here: https://archive.ph/20200214011034/https://factfinder.census....

Of that 41 million, 24.6 million "Speak English only or speak English 'very well', which is 58.9%. Of those under 18, that fraction goes up to 81.1%

For comparison, other Indo-European languages has 69.3% and 81.5% for those under 18. Asian and Pacific Island languages: 54.1%/75.4% Other languages: 69.0%/78.7%

It's not a perfect proxy for the claim about the loss of language with each generation, but it's a good approximation. The pattern is similar across all languages (and the difference between Spanish and other Indo-European languages is negligible). I've read about research that has more explicitly found that there is no unique pattern for Spanish in the U.S.

What you're seeing is not an indication that Spanish has a different pattern, but that there are more Spanish-speaking immigrants and are a more visible immigrant community to outsiders. My great-grandparents settled into communities of Czech and Slovene speakers and had children who were fully bilingual while of my parents' generation, only my father has any facility with Czech, which his mother credited to his being effectively raised by his grandmother in his early years. My own Czech knowledge doesn't extend much behind, Promiňte, prosim, rozumite anglický?

You can find communities where the first language is Chinese in almost any sizable urban area. There are parts of Chicago where the first language is Polish, but as the community is smaller and less visible to outsiders, most people don't even realize it. Los Angeles has numerous linguistic enclaves. When Pope John Paul II visited Los Angeles, what most excited the pope was that the Archdiocese offered Mass in more languages than any other diocese in the world. (Non-English church services are a big indicator of these linguistic communities).

Though decreasing now, German was kept alive across generations in various places in the U.S. in the 19th and early 20th centuries:

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

Switzerland seems to have done pretty well with multilingualism over the past few centuries.

I think the comparison is not fair, due to economic, ethnic and historical factors that make Switzerland not a fair metric for any other country to measure up to.

If we take just the language, we're comparing (French, Italian, German) against (Ndebele, Pedi, Sotho, Swati, Tsonga, Tswana, Venḓa, Xhosa, Zulu and Afrikaans). We're comparing the official languages of 3 world powers with very good life prospects for their speakers and those that kinda can do it, against 11 languages that have no value outside of 'talking to grandpa' or being able to read ancient texts.

Maybe I'm biased and perhaps I'm coming off a bit racist, that is not my intention. I just want to point out what I'm seeing here.

You could compare it to India.

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

I can understand that comparison a bit better, thank you.

We don’t really mix that much though. I’m from the French speaking side, when you live there you basically don’t go to the German or italien speaking side outside of vacations or specific events (also, transports are really expensive, that doesn’t help). And for young people it’s common to speak in English as an intermediate language between regions. I can also say that I had a decade of German courses in school and got absolutely nothing from them.

The experience is a bit different if you live in a bilingual canton but people are still mostly speaking one language.

Switzerland is a country of valleys separated by mountain ranges.

As i understand it, each isolated valley is pretty monolingual.

Switzerland also borders countries using those languages - it seems natural that linguistic borders wouldn't follow political borders especially well.

In Lebanon, there’s still a considerable armenian community that came over from the 1916 when the genocide happened.

They are very successful but almost always speak Armenian on top of the other 3 languages lebanese speak (lebanese, english, french).

They’re generally fluent but its not uncommon to detect an accent in armenian -lebanese even in recent generations.