@Cirsium - I'm surprised at your two groups of linguists. Linguists usually observe language use rather than lay down the law about it. And in any case I would say that anyone saying words with foreign roots must take the original plural are wrong, bot equally so are those who say that the opposite is true.

No doubt the vast majority of words that have come into English from other languages (which means about three-quarters of the words in the English language) take a regular English plural. But in any language, but especially in English (ask any foreign learner) there are always exceptions.

As some have already mentioned there are all those Greek-based words with a -sis ending - analysis, basis,crisis, ellipsis, hypothesis, oasis, psychosis - where the -es plural ending is standard natural English, perhaps because it's easier to say than -ises. Personally I prefer curricula (probably because that's the way I've always heard it), but obviously I'd never say musea. I think we need to take each word on its own merits rather than make hard and fast rules either way.

@ArjSaj - I take your point about Romeo and Juliet's love where we only need one possessive noun when two people have joint possession of something, but I don't think it works for pronouns. Would you say 'this is me and Jenny's bedroom' or 'that's him and her house'? I think not. So I would suggest it's the same with 'me and Gregg's child'. And as you say, it could be rather confusing.

Try reversing it, because actually I would say 'this is Jenny's and my bedroom' or 'this is Gregg's and my child' (if I'm the mother). But in standard English, at least, 'this is Jenny's and me bedroom' or 'this is Gregg's and me child' wouldn't work, although 'Juliet and Romeo's love' does. So I'm afraid I don't think you can necessarily extrapolate pronoun behaviour from the way nouns work.

@jayles -I'm sure you're right in a more specialist sense, but I think Noel's got it as a more general use, and that's the one dictionaries give:

having a firm basis in reality and so important, meaningful, or considerable
- there is no substantive evidence for the efficacy of these drugs - Oxford
The family appeared at the press conference but made no substantive comments - Macmillan
The State Department reported that substantive discussions had taken place with Beijing. (Longman)
Substantive research on the subject needs to be carried out. - Cambridge

Firstly, this sounds like spoken English to me rather than written language, and I think Cristina knew perfectly well what the questioner meant and was simply having a bit of a joke. And in any case there is no rule that says that you' have to use commas instead of 'and' between items; it is simply a convention to replace 'and' with a comma.

Personally, what I find tedious is when people take it on themselves to correct someone else's grammar uninvited.Just thought I'd point that out

I can only assume the reason you've given yourself that particular moniker is that you like to make a drama out of (a grammatical) nothing.

@ElktoothChain - My idea of descriptivism is that you make your case and support it with examples, not simply insult people and talk down to them. And perhaps say something specifically relevant to the topic.

@Rosewood11 - one small problem, 'pled' doesn't appear in the KJV, whereas 'pleaded' does, three times, two of which could be likened to the legal sense.

Blessed be the LORD, that hath pleaded the cause of my reproach - Samuel 25:3
O LORD, thou hast pleaded the causes of my soul; - Lamentations 3:58
Like as I pleaded with your fathers in the wilderness of the land of Egypt - Ezekiel 20:36

http://www.kingjamesbibleonline.org/search.php?q=pleaded&hs=1

@Skeeter Lewis - I think it was a case of partially changing what I'd written and then changing again and not checking it properly, so oops, red face - 'it might matter to jayles and me'

@Nelson - perhaps not authoritative but this might interest you, and seems to agree with what others have said on this thread:

'The origin of “I’m just sayin’” is not clear, but most paths trace it back to Yiddish humor. “I’m just saying” was the way some Jewish vaudevillians ended a joke. The phrase was popularized by two comedians in the 1980s: Paul Reiser and Eddie Murphy.'

http://prestwickhouse.blogspot.com/2010/01/plain-english-im-just-sayin.html

@MagicMatt - "So I'm pretty big on correcting other people's grammar when they misspeak." - And you think that's something to be proud of?

You make a great play on the fact that the noun is 'thought' and not 'think' - this is what ex-professor of English at W.S.U Paul Bryans has to say:

'Here’s a case in which eagerness to avoid error leads to error. The original expression is the last part of a deliberately ungrammatical joke: “If that’s what you think, you’ve got another think coming.” '

http://public.wsu.edu/~brians/errors/thing.html

And maybe when someone uses an idiom you haven't come across which you suspect might be British, it might be an idea to check with a British dictionary before accusing them of being ignorant. There are lots of things Americans say which we don't, but we don't usually accuse them of sounding stupid.

http://www.macmillandictionary.com/dictionary/british/think_41

If you really think it's fun to correct people who 'misspeak', it might be worthwhile doing your homework first, or you're the one who's likely to end up with egg on your face.

@JJM - It doesn't matter for native speakers in the course of normal conversation or writing. But it might matter to jayles and I as EFL teachers if one of our students asked us to explain. It would also seem to help jayles understand why his Korean students are making certain errors.

And it might also matter to those native-speaker students, especially in the States, whose work is marked down for including the passive, simply because their teacher can't tell the difference between a passive and an adjective.