Are there other ways to say "native speaker" which also allow a bit more flexibility as for when the speaker learnt that language?
A child of an immigrant family who moved to the US when he/she was 5, for example, who speaks fluent and flawless English now but English is technically their second language nonetheless should be called what?
I understand that I could still just call them a native speaker. But to me, and I don't know exactly what it is, but just something about the word "native" doesn't make it sound quite right, not wrong either, but I feel like there could be a better way to say it.
Something like a "fluent speaker" could do the job but it can also be used to describe someone who learnt the language as a completely foreign language and just became fluent in it, which makes it not appropriate for the purpose I'm trying to use the word for.
So by "flexible", I think I mean what do I call somebody who's basically been speaking that language for their whole life? Whether it was technically their first language or second.
Edit: I understand it’s not incorrect to consider this child a native speaker. But it’s that “not incorrect” part that made me ask this question. If I use the term “native speaker”, I feel like it kind of requires me to specify what I’m counting as “native”. So I was wondering if there was a term that would immediately let people know the level of flexibility I’m allowing/implying without me having to specify it