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.)