Sámi languages
"The Sámi languages ... are sometimes considered dialects of one language", says Encyclopædia Britannica; those who speak one Sámi language, [mostly] do not understand other Sami languages; "[t]he Sámi languages share many features (or things,) with the Baltic-Finnic languages (Finnish, Estonian, Karelian, etc.)," but "they cannot be closely related to any of these"... "[T]heir grammars are similar to that of Finnish, although their syntax has been influenced by the Scandinavian languages."