espanjankielisiin
The term "espanjankielisiin" is the plural partitive case of the Finnish word "espanjankielinen," which translates to "Spanish-speaking." In Finnish grammar, the partitive case is used to indicate a part of a whole, an indefinite quantity, or in contexts that express an action affecting only a portion of something. Therefore, "espanjankielisiin" specifically refers to "to/into/among some Spanish-speaking [people/things]" or "some Spanish-speaking [people/things]."
This grammatical form would appear in sentences where the focus is on a portion or an indefinite