@DRae - there has already been a lot of discussion about the 'put' group of verbs before your comment. Why make something irregular when a perfectly good regular version exists? The trend in English is towards regularisation, not the reverse. Why add a possibly ambiguous form when there is absolutely no need?

There isn't actually much disagreement about 'texted' except in forums like this:

'if she was going to go she would have texted us' - Oxford Dictionaries Online
tr.v. text·ed, text·ing, texts - 'She texted me when she arrived.' American Heritage at the Free Dictionary
' He texted a long wish list to his parents' - Random House at Dictionary.com

As for hanged and hung - they are traditionally used in different contexts (also discussed above), although that distinction seems to be slipping.

@BGriffin - Sorry, but all this stuff with an unidentified 'it' makes no sense whatsoever to me and I have to rather agree with Brus' pithy comment. Somebody just doesn't go to the store with an it, they go with someone or perhaps their dog.

If this is a character you've made up, why it (especially as it's apparently you - are you an it)? Why not he or she? Again there is not one single entry for 'it and I are' on Google. And again the logic doesn't hold up - I can't go to the store with myself. But if you insist - 'It and I are both me'. However, no sorry, I don't understand the possibility of it arising, or really what you're on about, at all.

@BGriffin

"I just have to be ____" - I didn't exactly answer your question the way you wanted because I would never say me or I there. The standard way to repeat the pronoun is with a reflexive.

"I am _____" - again I can't imagine anyone saying me or I here. What does it mean? Mind you the Beatles get close to it in 'I am the Walrus' - 'I am he as you are he as you are me'

OK I see there are several references to "We have seen the enemy and it is us" - and that's fine - the enemy is us.

But in "With that insight, I realized that in this context, it and I are both _____" , I have no idea what it refers to. What is its antecedent. OK, presuming it is some sort of problem already mentioned, again I would never say I or me here, but "it and I are one and the same thing"

And the same with "It turns out, all along it wasn't some other person holding me back. It and I have always been, currently are, and always will be _____" - I have no idea what or who the second it refers to; what's its antecedent?

Unless you mean something like "It turns out, that all along it wasn't some other person holding me back. It has always been, currently is, and always will be me" (purists will probably say I, but that sounds unnatural to me)

I think you can say 'it is me / I' - 1 = 1, but not 'it and I are me / I' where1 + 1 = 1. It sounds neither logical nor natural to me. Incidentally, none of these get a single hit on Google - ''it and I are both me', 'it and I are both I', 'it and I are me' , 'it and I are I'. Sorry, but it just ain't English :)

@Skeeter Lewis - Thanks for that, I'd never realised that's where it came from. You can still find modern examples of it being used in the more general 'legal' sense at Google Books -

"His forensic skills helped him to a number of courtroom victories, but they left him with little sense of personal fulfillment" - D.W. Griffith's the Birth of a Nation, London Melvyn Stokes University College - 2007

This one is not so much legal as going back to idea of a/the forum - "Nixon was an effective debater, but his forensic skills were overwhelmed by the television images of a sweating, shifty—eyed politician which marked the return of the original Tricky Dick" - Presidential Upsets, Douglas J. Clouatre - 2013

And one, appropriately enough, from an account of Ancient Athens:

"His forensic skills had been tested in his litigation with Callippus and his neighbour, Nicostratus" - War, Democracy and Culture in Classical Athens, David M. Pritchard - 2010

'English is the worldwide language of business' - I know because that's how I 'tout' my trade, and I have seen enough business correspondence done in exercises and real life to know that grammar is a far bigger problem than spelling. If you really want to help foreign learners, it's the grammar you need to overhaul, not the spelling.

@BGriffin

"I just have to be ____" - 'me' or 'I'? I would suggest neither, but - 'myself'
"I am _____"- 'me' or I''? again neither - 'I am what/who I am'

I'm afraid I don't understand your last two sentences. How can 'it' and 'I' be 'me' or 'I'. Sorry, but I can't make out the sense of these sentences

@jayles - I didn't say that 'are' would top 'is', just that the difference between AmE and BrE is more marked. As I've said before - Ngram is based on books, and even BRE speakers are likely to use singular more in formal written texts.

@HS - 'A political party contains many members certainly makes more sense than a political party contain many members. Or don't you agree with that either?'

Not only does the first sentence make sense, the alternative is both ungrammatical and without any sense, because 'contain' is a state verb; it doesn't describe an action carried out by or its individual members or their fortunes.

Sorry, but this is another straw man: nobody who says 'the party are doing well in the polls' would use a plural with 'contain'. You can only use a plural verb when you could substitute a plural pronoun for the noun. You can obviously say 'They're doing well in the polls', so you can equally say 'The party are doing well in the polls'. But of course you can't say 'They contain many members'; that would mean each member contains one or more members.

Yes, I usually treat the media as plural, as we're generally talking of a group of organisations. But media is a special case, as it can be seen as uncountable, singular or plural.

Incidentally, I'd love to know where you get your 'ten to fifteen percent of British English speakers' from.

From a couple of Scottish educators:

'Rule XXIX. — Collective Nouns take a singular verb or a plural verb, as the notion of unity or of plurality is uppermost in the mind of the speaker. Thus we say : "Parliament was dissolved." "The committee are divided in opinion." '

The English Language: Its Grammar, History, and Literature, by J.M.D. Meiklejohn.
Meiklejohn was Professor of the Theory, History and Practice of Education in the University of St.Andrews.

'Collective Nouns generally have a Singular Verb, but when you think more of the individuals in the group than of the group as a single whole the verb may be plural — e.g.

"The mob assembles."
but
"The mob throw stones."

Advanced English Grammar through Composition, London 1917, by John D. Rose, Rector of Kirkcaldy High School.

The teaching of collective nouns in British schools in the middle of the 20th century

Sir Lancelot Oliphant was a diplomat and the author of several grammar books for British schools, including A General Certificate English Course (1928). I've no idea how widespread the use of his books was, but the fact that this book was still being reprinted in 1966 suggests that his books were quite widely used. The book of his I'm going to quote from apparently sits on the shelves of arch-prescriptivist Neville Gwynne, so that might also tell us something of his status. In 'English Observed, Common Errors in Written English', published in 1946, he has one question related to collective nouns:

"'The frenzied mob was now seen at their worst.'

(A collective noun in the singular may be followed by a verb in the singular or the plural, according as we regard a thing as an undivided whole or as consisting of individuals that compose the whole. But the noun cannot be treated as both singular and plural at the same time. Write, ‘The frenzied mob was now seen at its worst’; or, ‘The frenzied mob were now seen at their worst’.) "

As in all the traditional grammar books I've looked at, he says that both singular and plural verbs are possible. What most concerns him. and the same goes for the grammarians before him, is that any pronouns should agree with the verb, and that the sentence should be grammatically consistent.

Rather like Fowler before him, Oliphant seems to have been a strange mixture of prescriptivist and descriptivist. In a section called 'Words commonly misused' as well as the usual suspects like literally and decimate, he lists the following - the comments after each are from Oxford Dictionaries Online (ODO):

aggravating - shouldn't be to mean annoying, only to make heavier or worse
ODO list the annoying meaning as informal but point out that it dates back to the 17th century 'and has been so used by respected writers ever since', although disliked by traditionalists.

awfully - shouldn't be used to mean very - awful means ‘inspiring fear or reverence’
ODO list Oliphant's preferred meaning of awful as archaic.

demean - doesn't mean lower or debase yourself - it simply means conduct yourself
ODO gives the debase meaning and makes no mention of Oliphant's definition

nice - means ‘fastidious’, ‘delicate’, ‘refined’, and should not be used indiscriminately to mean ‘pleasant’, ‘agreeable’, or ‘beautiful’.
ODO list Oliphant's preferred definitions as archaic

practically - shouldn't be used to mean almost (although it's OK in conversation). His definition is more like 'in practice'
ODO list almost as its main meaning, and also in a practical manner, but not in practice

I certainly remember being taught something similar about nice at school. It just goes to show, though, for those of us who were at school rather longer ago than we care to remember, not everything we were taught in English is particularly relevant today.