Dans & à and being specific?
Specific location: Il mange dans le restaurant. Unspecific location: On vit à la campagne.
Why 'le restaurant' is specific but 'la campagne' is unspecific? If you think like English (how Duolingo explains it back there) both have 'the' and the listener probably knows which restaurant or county they talk about. Don't 'le/la' make something specific in French?
I don't think specific vs unspecific can be equated to definite (le/la) vs indefinite here. I would say (without being a fluent French speaker) the difference is that le restaurant is a more confined space than la campagne. If someone asks where you are, "at the restaurant" (which you have probably mentioned before because of the "the") is a more specific answer than "in the countryside" or "in the United States" which also use the definite article.
"dans" means in. Il mange dans le restaurant = He eats in the restaurant.
"à / au" means at / at the. Il mange au restaurant. = He eats at the restaurant.
You can say "On vit dans la campagne" as well as "On vit à la campagne", but it doesn't mean exactly the same thing.
JArgeles, then what is the difference between "On vit dans la campagne" as well as "On vit à la campagne" then?
I'm French so I just know it like that but put into words, I would say that we use "On vit dans la campagne." less than the other example but it is still correct. "On vit dans la campagne" would mean that "We live in the countryside". "On vit à la campagne" means that "we live at the countryside."
It's different prepositions, that we use in different cases than in other languages...