languages vs dialects

A question that, I think, is more interesting to laypeople than to linguists themselves is, “Are [insert two language varieties here] separate languages or dialects of the same language?” The judgement is often made for cultural or political reasons rather than actual linguistic ones. Nationalism is regularly a factor in arguments being made in either direction. There is that well-known pithy saying, A language is a dialect with an army and a navy, that sums up these extralinguistic factors.

Insofar as linguists even try to answer the question of whether two lects are separate languages or dialects of the same (as opposed to just describing and comparing lects, which is more familiar territory), the determining factor is said to be mutual intelligibility. That is, if speakers of two different lects can understand each other, each speaking their own lect, they speak the same language. If they cannot, they’re different languages. Un­for­t­u­n­ate­ly, understanding is a bit fuzzier than a binary “can or cannot”, and depends a bit on the speakers’ cooperativeness, the topic of conversation, the broadness of each speaker’s vocabulary, and so forth. Also, sometimes intelligibility can be asymmetric, where one of the speakers understands the other much better than the other understands them. So, in reality there are a lot of these edge cases, where two varieties can be described as dialects or separate languages, and it really kind of depends.

Many of these edge cases exist in dialect continuua, where basically countless related dialects descended from the same ancestor language are spread out over an area, and neighbouring dialects are generally mutually intelligible while more distant ones are not. Even if you realise the area encompasses more than one language on the mutual intelligibility criterion, it’s basically impossible to work out how many there are, because it depends where you draw the lines, and ultimately where you draw the lines is arbitrary. Often what ends up happening is either “this whole area is one language even though not all speakers understand each other” (like with Arabic, Hindi or German dialects), or “one language per country or per region with an independent literary tradition” (like the Romance languages, Slavic languages, or Scandinavian languages). Ausbau sociolinguistics exists to try to explain these different ways of defining languages.

Some other examples of lects in this fuzzy border area with each other include:

  • English and Scots: As an Australian speaker of English, “full Scots” is definitely not intelligible for me – I would call that a separate language. That said, virtually all Scots speakers these days are completely bilingual with English, and so much of their casual speech would sit on a continuum somewhere between Standard Scottish English and “full Scots”. I still think that makes Scots a separate language (especially given its independent literary history as well), but it’s fair to acknowledge that many Scottish people don’t share that feeling.
  • Hindi and Urdu: As is well-known, these languages are basically the same in the basic, everyday, colloquial register. However as you get into more formal language, differences emerge (Urdu borrows more higher-register words from Persian and Arabic; Hindi prefers to derive new words from Sanskrit roots), and they’re written in different scripts (Devanagari for Hindi and Arabic for Urdu).