> So first off I'm explicitly downplaying the phonological side of things here. This entire thread has been about the fundamental grammatical and vocabulary differences rather than phonological differences

You are single-handedly dismissing the whole body of research that has allowed us to arrive at the realisation and evidence of the historical progression of Chinese languages (please do note the use of plural) in the first place. Owing to the isolating nature of all Sino-Tibetic languages and, critically, a millenia long use of the logographic script that has no other known precedents, the phonological and comparative regional linguistic studies have been the single main instrument that has made the reconstruction of Old (Ancient) and Middle Chinese languages possible. Which also includes the understanding of the grammar of Old Chinese and which was vastly different even from that of Middle Chinese.

> So leaving aside the phonology, I offer a rough idea here of why the Song vernacular is essentially Mandarin: https://news.ycombinator.com/item?id=29528008

No. In the context of this particular conversation, leaving out the phonology is not possible due to the peculiarities I have mentioned above. It is also not possible to provide a self-reference as a reputable reference or a proof of your own claims.

I have collated a couple of responses you are self-referencing to in another thread below, anyway.

> 2. The near demonstrative is 這 (also spelled 者, 遮, or otherwise) and the far demonstrative is 那. While other demonstratives exist (as is the case even in modern Mandarin) these are far and away the most popular, regardless of region.

The source of https://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?wo... does not support your assertion concerning 那 and states that the use of 那 as a distal demonstrative had been established by the Tang era, i.e. before the emergence of Middle Chinese.

> 4. The copula is always 是.

The source of https://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?wo... contradicts your statement and states that 是 had already been used as a copula during Han dynasty times. Which also predates the emergence of Middle Chinese:

至於「繫詞」意義的「是」，最早出現於戰國的《孟子．告子上》：「公都子問曰：『鈞是人也，或為大人，或為小人，何也？』」趙岐注：「鈞，同也。」意謂公都子問道：「同樣是人，有些是君子，有些是小人，甚麼緣故？」（楊伯峻）。東漢漸多見，如《論衡．死偽》：「余是所嫁婦人之父也」。佛經傳入以後，才全面流行。

> I don't believe this, at least not without more research. The core vocabulary of…

Please do provide references to peer reviewed scholar views and research that can substantiate your beliefs. I am eager to read through them and contemplate.

Summing it up, so far you have presented an alternative timeline of the history of Mandarin that has had a supposedly continuous history of existence starting from (or even predating) early Middle Chinese. Mainstream scholar views and scientic studies as well as existing evidence do not support your theory which is a fringe theory at best. You have also eschewed any reputable references that would add credibility to statements you have made so far. Therefore, I propose we settle on this: you have provided opinions that are of your own, and that is that. Which is not to say that your knowledge of Mandarin appears to be remarkable and is commendable irrespective of however you choose to use it to suit your narrative.