What language has the most complex grammar in the world?

To what extent did the structure of Proto Indo-European influence Western ideas about grammar and languages?

• What I mean is that PIE happened to be a) a very fusional, morphologically complex language with a lot of morphophonological alternations, allomorphy, cumulative and multiple exponence, portemanteau morphemes etc, and b) the ancestor of today's most widely spoken languages. It seems to me like it was as fusional as languages can be (correct me if I'm wrong), and since it can't possibly become even more fusional, loss of morphological complexity and evolution towards a more isolating structure - the final step in the grammaticalization cycle - seems inevitable, and this is indeed what happened in IE languages since PIE. Therefore people in Western Eurasia - and recently people all over the world - have been, and still are, observing loss of inflection, reduction of complex paradigms, mergers which created syncretisms etc, and this is usually considered language decay, decline of not only Western language but also culture, tradition, values, education and whatever. Of course individual grammatical features and categories evolve at different paces, and therefore different pieces of grammar within one language are at different stages in the grammaticalization cycle, and a lot of IE languages have seen grammar innovations which restarted the cycle, like the English tense/aspect system, but I think generally speaking loss of inflection is more common in IE languages than in other languages. My question is to what extent this random coincidence - the structure of PIE - influenced Western ideas how language evolves, particularly the idea that archaic, ancient languages are somehow superior to modern language, and that language is constantly degenerating "until we will communicate by primitive grunts" (I'm sure you are familiar with this kind of complaint). It seems to me that people are more likely to think so if there is a long-lasting prestigious widely known language such as Latin which is daily used by scholars/the clergy/the elite, and daily compared to modern Romance languages. I wonder how European ideas about grammar would have evolved if PIE, and consequently the dominant language used by scholars as a lingua franca and for liturgical purposes, would not be more complex morphologically than its modern descendants. The other thing I was thinking about is that until modern linguistics emerged Western grammarians and philologists - both in antiquity and in the Middle Ages - focused very much on morphosyntax at the expense of phonology. Is this related to the fact that Latin was very complex in morphosyntax but had a comparatively simple phonology? This part of the question is less about PIE but more about the European languages which emerged from PIE. AFAIK most Indian IE languages largely expanded their plosive inventories because of Dravidian influence, whereas European languages even reduced the distinctions inherited from PIE, and AFAIK the common alphabetic order in Indian scripts reflects the systematic relations between segments (as opposed to the random order in the Latin alphabet) and therefore means that Indians have consciously known about phonological features for quite a while. Therefore I'd appreciate answers with insights about Indian grammar tradition and comparisions to Western grammar traditon, as well as information about other civilizations which have not been influenced by PIE, such as Chinese. The assumption is that Western culture and civilization would have evolved just the way it did in reality, except for the language. What if the Indo-Europeans had conquered Western Eurasia, introduced horses and patriarchy etc., but spoken an isolating or agglutinating language? Or a language with a modern Caucasian phonology?

• Answer:

  I think the template is less PIE and more Latin. There were many innovations in Latin compared to the classical IE structures that can be seen in classical Greek and Vedic Sanskrit. (I am thinking primarily about the verbal system, which is based almost completely on aspect, with tense an afterthought, in Greek and Vedic Sanskrit, where the Latin system is much more focussed on tense.) But indeed, Latin kept rich inflection. (Much less rich than PIE / classical Greek / Sanskrit, or the modern Slavic languages, but rich enough). And this of course gave rise to centuries of strange language didactics, teaching languages like English or Japanese following Latin paradigms. One point typical in western consideration of languages is the focus on morphology. And that focus it shares with the classical Indian (Panini) view of grammar. If you look at a Sanskrit grammar of the 19th century (and these are still in common use today), syntax is a mere anecdotal afterthought. The reason that this distorted view could evolve in these two grammarians traditions, and that it even works is of course that the old IE languages are built around morphology. Notice that in the modern Indo-Aryan languages that evolved from Sanskrit, the loss of morphology can be observed as well. The classical Indian view of (Sanskrit) grammar is of course much more elegant, and, as has been mentioned often, resembles modern generative methods, while the western (Latin-centered) apparatus of grammar is distinctly old-fashioned. I cannot tell much about eastern views of Grammar theories. I can only contribute that the Japanese phonological system (Their presentation of their system of syllables "https://en.wikipedia.org/wiki/Goj%C5%ABon") is built after Sanskrit (which was known via Buddhism). I have no idea if this influence went further and perhaps might have given rise to a (hypothetical) completely crazy analysis of Chinese Sanskrit-style. I doubt that it happened that way.