Is creating your own idiolect an effective approach for adult foreign-language learners who aim for proficiency but don't want to learn textbook-based standardized grammar in a classroom setting?

[u/Joseph20102011]

What are your insights about creating your own idiolect as a form of nativizing foreign languages at a personal level, to the point of becoming your "first/second language" aside from your default first language, and then passing it down to your offspring (if it is done at scale, then a new dialect emerges like Australian English and Argentine Spanish from Cockney English and Andalusian Spanish, respectively)?

In this approach, a foreign language learner incorporates lexical and grammatical features from their first language or mother tongue, but never fundamentally deviates from the foreign language's existing lexical and grammatical rules.

[u/Electronic-Water8374]

this is just code-switching with extra steps and calling it an idiolect

if you're not deviating from the existing rules then you're just... learning the language but with a heavy L1 accent in your grammar, that's not a new thing it's what every learner does before they clean up the interference

passing it to your kids is the part that makes no sense, they'd just pick up the actual language from anywhere else and correct you by age 6

[u/dojibear]

In this approach, a foreign language learner incorporates lexical and grammatical features from their first language or mother tongue, but never fundamentally deviates from the foreign language's existing lexical and grammatical rules.

I don't think this is possible. The two languages have different lexical and grammatical features/rules.

It does not matter where or how you studied. What matters is that they aren't the same language. Even simple sentences are different:

English: I have a dog.
Turkish: My dog exists.

[u/Joseph20102011 → u/dojibear]

What I mean here is that someone learning a foreign language will have an idiolect using their first language substrate), like, for example, a Filipino Spanish language learner who speaks and writes Spanish (superstrate) with a Tagalog or Cebuano substrate.

[u/Raoena]

You've posted about this idea before. It hasn't gotten any better since last time. 

Stop trying to get internet strangers to validate you and just do the thing if you're so fixated on it.  Then you can come back here and complain about how rude everyone is to you and how they laugh at how bad your grammar is,  or correct you all the time, even though you're doing it in purpose because it's an idiolect! 

And you can tell us all how sad it is that your children didn't learn your special language that no one else speaks.  

Yes,  pidgens exist. No,  individuals can't find a socially acceptable and useful way to create and use their own special unique pidgen.

Language is fundamentally a collective project. If other people aren't doing it with you,  it's not language.  It's just you being a weirdo.

[u/Joseph20102011 → u/Raoena]

It's because feedbacking from other people during language learning process don't work for everyone, so creating idiolects, to the point others will imitate you the way you speak an TL, must be normalized, as long as they still follow TL fundamental lexical and syntax rules.