FWIW, Armenian used to be classified as a Persian language because its vocabulary is extremely close to Persian languages. Later, modern linguistics understood

FWIW, Armenian used to be classified as a Persian language because its vocabulary is extremely close to Persian languages. Later, modern linguistics understood that (using comparative methods) Armenian is a language isolate within Indo-European family and has no relation to Persian languages (other than Proto-Indo-European). What confused linguists for about a century is that Armenian happened to borrow almost its entire vocabulary from Persian!