and how much (or not) they've changed.

Chinese has changed dramatically from Classical Chinese to Modern Chinese. Welsh on the other hand has not changed as much. There is however, like Chinese, a dramatic difference between literary and spoken languages in both.

We've lost nominative absolutive constructions since the 1700s.

"Having gone to the store, Jerry stopped at a bar on the way home" usually means Jerry went to the store. That's the problem with the 2nd Amendment--it has that kind of construction, but the two subjects are different.

We don't nearly as often use verbal phrases as nouns: "That Jerry went to the store prior to his appearance at the bar cannot be questioned."

Shall/will have merged.

We've lost the subjunctive. It was still the colloquial norm when/where I grew up, so "It's important that witnesses be found to confirm Jerry's presence at the bar" is the only thing I can say (unless I'm asserting that we have found witnesses and their findability is what's important, "It's important that witness are found to confirm Jerry's presence," but that still sounds a bit weird to me).

Those under 30 or 35 have largely lost count/mass distinctions. It's such a grammatical requirement for me I can't even produce examples that would be grammatical for them--they all sound like gibberish to me.

We've acquired in the last 20 year the ability to free use the present progressive aspect of verbs that show cognitive or emotional states. "I'm not liking that" was grossly unsayable 50 years ago in mainstream English. "He isn't understanding what that could mean," likewise. "Snuggles is really loving that petting" is overkill.

In KJV English--not always au courant in 1611, but still considered Modern English (just "early Modern&quot we still had the auxiliary "be" for many verbs of motion. "I am come" instead of "I have come" (that they sound like they must mean different things is just modern ears trying to give the first a meaning using modern grammar, instead of recognizing it as now ungrammatical).

It wasn't just prescriptivism that said "Jerry's appearing at the bar was noteworthy", now become "Jerry appearing at the bar was noteworthy"--in both cases, "Jerry's appearance at the bar was noteworthy" is what's meant, even if the latter makes it sound like it was Jerry himself meriting being noted.

Who/whom merger, and the loss of a distinction of that/which in subordination, is pretty much complete.

Mencken first noted, as far as I'm aware, urban English's propensity to only inflect the first member of two conjoined pronominal phrases. "Between you and I" is normal in colloquial big-city speech, and spread from there. Some of what he described was transient, other parts are standard. https://www.bartleby.com/185/41.html

A few other things crossed my mind as I was typing, but they've found other minds to muddle.

A lot of these things are changes around the edges, or parts of on-going changes, or perhaps restricted a bit geographically or socially, but they count, too. That's not counting some of the odd uses we see that are probably not going to last--for instance, "because" + noun ("Why stop a Chuy's? Because tequila&quot . It also doesn't count imports from AAVE, "This be like crazy." Or even my favorite innovation, heard not too long back, where "ish" went from its usually place as approximate number (five-ish, ten-ish) and approximate adjectival description (greenish) to verbs to show incompleted actions reluctantly admitted ("it's done ... ish"; "I have it read ... ish).

Nominative absolutive constructions sound normal to me.

In American English, "shall" has not so much merged with "will" as disappeared. I've been assured by a linguistics professor that youngsters never ask "shall I open the door for you?". Maybe that's because, in such questions, "shall" and "will" can't be interchanged.

I can't believe we've entirely lost the subjunctive, although some forms of it are now not much used in speech. "If I had been paying attention, maybe I wouldn't have fallen for the scam" sounds normal to me. "Had I been paying attention ..." sounds stilted. I believe "subjunctive" in English isn't syntax, it's semantics. Maybe we call it subjunctive because we used to wish that English, like Latin, had subjunctive forms, and similarly for "future".

I say "these data" (not "this data&quot , "these criteria", "this bacterium", etc. But note that "datum" is only a technical term in surveying.

The last vestiges of the case system in English are breaking down. "It's me" is standard. To avoid gender bias, many people now say and write "they", "them", and "their", as singular forms. I much prefer "he or she", etc.