Is there a term for the prestige language that's learned more-or-less natively?

Question

I've seen here a lot of use of L1 and L2 to distinguish between the mother tongue, and the language learned later in life. This makes me wonder if there is any good terminology to refer to the languages in the following type of situation, in the context of language learning:

• One language (let's call it A for now) is used in the household and in day-to-day conversations with friends and strangers.
• Another language (let's call it B) is used either exclusively, or much more than A, in school, government, and the media. It is, to some degree, a prestige language where the person in question grows up.

A is clearly an L1. Since exposure to B starts very young, is it an L1, too? Or an L2 because becoming conversational in it happens at a later age than with A (for most children), usually in a school setting? Or is there better terminology for these?

Some examples of this situation are Wolof and French in Senegal for native Wolof speakers, and Creole and Portuguese in Cape Verde or Guinea-Bissau for native Creole speakers.

Sometimes to keep things simple (or attempt to improve their chances of being hired) people will just call B their "native language". But that doesn't seem useful for talking about language acquisition for people in these situations, because B is not quite as native for them as A…and especially when you want to discuss teaching or learning B. In cases where the language A is a creole of B, there's the term superstrate for B, but I don't know if it's used for discussing language learning, or if it can be used when A isn't a proper creole.

(There are more complicated situations, too, such as where A is used in the household and with some friends, but there's another language, different from both A and B, that's used with most strangers in cities. The Fula in Senegal or Guinea-Bissau, for example.)

Answer 1

The situation you are describing is called diglossia. Language A is the vernacular. The term may refer to a dialect as opposed to the literary or public forms of the same language ("African-American vernacular English"), as well as to a national language as opposed to a lingua franca (such as Latin in the medieval times).

Answer 2

Frankly, I think a lot of this is embedded in the term "prestige language" as it is. Being learned later is usual for prestige languages, since they're are usually taught in school and not used at home,

In fact, it took me a second to work around your question because "prestige language" equates to "more or less native" in my head. There will be people with higher levels of proficiency in the prestige language (city dwellers, government officials, etc.), and there will be some with less (usually more rural populations).

I would think that most people in Senegal would understand the context when someone tells them what languages they speak, since it's part of their identity.

Outside of the diglossia, one could always say "Native, Quechua; Fluent, Spanish." That isn't misrepresentation, and is probably the most accurate description.

Tl;dr No, because context would usually make clear what the situation is. Personally, I would call it an L2, since you most likely received formal instruction.

However, that's not a very helpful answer, and there should be a word for it. Maybe you could get away with L1.5?

Disclaimer: I don't live in a diglossic situation, so I would be curious to know if there are words for this in various bilingual societies across the globe.