When did British and American grammar diverge?

Consider these sentences:
American: Virgin Atlantic has daily flights between New York and London.

British: Virgin Atlantic have daily flights between New York and London.

American English treats a collective noun (in this case the company Virgin Atlantic)as singular whereas British English treats it as plural.

Since American English presumably came from British English, they both must have had a common rule of grammar once upon a time. Can anyone tell me who changed the rule and when?

Even back in the Colonial era there were people in England complaining about those uncouth American colonials mangling the English language. I know he’s not especially well regarded around these parts, but I’m a huge Bill Bryson fan and found his books Mother Tongue and Made In America to be fascinating reading on the subject of the evolution of the English language and the American divergence thereof.

My recollection is that Noah Webster’s sometimes-idiosyncratic spelling choices influenced many orthographic differences in the US from the UK, but I don’t know whether he was a grammarian as well.

Not necessarily. I think it would take a real language scholar to answer the question, but it is necessary to consider other likely possibilities:

(1) Both forms were extant in both countries in the colonial era and for one reason or another, one became preferred in one country and the other in the other. In other words, there was no set rule at the time.

(2) What is now the American standard was the standard in Britain and it is the British standard that later diverged.

The problem is that you can’t take Bryson at face value. He’s essentially a linguistic gossip columnist. The stories are fun, but he’s not reliable.

I think you’re giving the english language more credit than it deserves in assuming it had a common rule back in the day.

There has never been an official authority guarding the english language in the way that french has. Which is probably why most of us are confused about what the ‘rules’ are supposed to be.

I’ve just done some Googling to find anything relevant to this topic. If you want to do some searching yourself, try putting the words “English,” “British,” “American,” “formal,” “notional,” and “agreement” into a search engine. Here’s the most complete discussion I could find about how this difference of grammar works at present:

http://www.psych.illinois.edu/~kbock/bockpubs/Bock%20Butterfield%20Cutler%20Cutting%20Eberhard%20Humphreys%202006.pdf

It’s not clear even to linguists how the difference between British and American English works in this case at the present time. I can’t find any evidence that anyone has tried to figure out how the difference came about historically. I suspect that there’s no way you can get an answer to this question on the SDMB. You might try to see to see if there are any message boards online that are for experts in the history of the English language.

Just to throw in some more variables - British English was not monolithic in its grammar etc at the time of the colonies - and the colonists were not a cross-sectional sample of (or entirely composed of) Britons.

Not to mention that a significant percentage of the colonists were Dutch, and the bilinguals of those could always have introduced a Dutch spin on the local English. (Possibly not relevant in this or any case at all, but it seemed worth mentioning as a possibility.)

British English is still not monolithic. It would be interesting to do a dialect survey (including Britain, Ireland, Canada, the U.S., Australia and New Zealand) on what proportion of native speakers prefer singular vs. plural verbs in various contexts.

There were large numbers of German and Scandinavian speakers in the U.S. as well, who also may have influenced American English.

I will write him” instead of “I will write to him
One hundred twenty” instead of “one hundred and twenty”. Likely both of these are German constructions.
Yes, this is she”. Sounds pedantic to us. “Yes, that’s me
Spent hulls” [shotgun cartridges] . Most likely from German, hulse

I don’t think the examples in the OP are good ones. British formal usage is generally to refer to companies in the singular. All the main UK newspapers would write “Virgin Atlantic has…”.

Example 1

Example 2

Example 3

The US/UK difference that jars with me is referring to bands in the singular. Band names always take the plural in the UK, so reading something like “REM is touring” or “Tool has released a new album” sounds very wrong.

REMs are touring? Really?

A quote from the last article cited:

“British Airways” has a plural form, but the singular “has”, “it” and “its” are used to refer to it. So that’s going in the opposite direction.

Companies like BA that have a “plural” name are tricky. House style where I work is still to refer to them in the singular: the fact that they are a company outweighs the style of their name.

So, “British Airways has lost millions because of the volcanic ash cloud.” “Dunkin Donuts has so far failed to catch on in the UK.”

What’s the US style for those?
Oh, and:

No, “REM are touring”. “Tool have released a new album”. “Your favourite band are rubbish”. I meant that band names take the plural form of the verb, not that we add an “s”.

American usage is to use the singular verb form in all these cases.

Ah. Yes. In North America we would say REM is touring, however we would also say The Stones are touring.

Being of a certain vintage I clearly remember:

" The Monkees is coming."

Yeah, yeah, I know it is a play on the band name and the TV show but…never mind.

We’re the young generation
And we’ve got Saddam Hussein …

Americans say, “John is in the hospital”, Brits omit the “the”. There are numerous small differences like that. But the one that irritates me is that the Brits seem to have lost the subjunctive. Where a book I cowrote had a large number of sentences of the form, “A necessary and sufficient condition that a category have [a certain property]…”, the British copy editor marked each one as a fault. To my ear, using “has” is such a sentence is just plain wrong.