@Hmmmm - redundancy has nothing to do with grammar; it's about style and usage. And in informal discourse there's nothing wrong with a bit of redundancy here and there. In fact in spoken language it often helps understanding.This preoccupation some people have with redundancy is really quite beyond me - it's part of what I think of as "English by numbers".

Oxford Advanced Learner's Dictionary:
everybody = everyone
anybody = anyone
nobody = no one
somebody = someone

The main entries are under the "one" versions, probably because we tend to use them more than the "body" versions in spoken language. And Google Books Ngrams suggests this also been very much the case in print since about the 1930s.

http://books.google.com/ngrams/graph?content=everybody%2Ceveryone%2Csomebody%2Csomeone&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=

I don't think any hypothesising can alter the fact that they are the same, and that the way we use them probably depends on the surrounding words rather than any nuance of meaning.

By the way, in dogreed's comparison of "God bless us, everyone" and "God bless, us everybody", I think that in the meaning he is suggesting for the first one, it should really be "God bless us, every one" - ie each and every one of us. So this doesn't prove any difference either.

Sorry again. That should have course read "which is better in negative statements", NOT "which is better in positive statement." Silly me!

Sorry, that's not distancing, but a polite form.

"Both the one-word form cannot and the two-word form can not are acceptable, but cannot is more common (in the Oxford English Corpus, three times as common). The two-word form is better only in a construction in which not is part of a set phrase, such as ‘not only ... but (also)’ " Oxford Dictionaries Online

@e2e4 - You bring up an interesting point about the question form, and as you say "cannot" doesn't work there, but for the very good reason that in question form when the auxiliary is not contracted, "not" comes after the inverted subject:

"Didn't she say she was coming?", but "Did she not say she was coming?"
"Haven't I seen you before?", but "Have I not seen you before?"
"Won't you do as I ask?", but "Will you not do as I ask?"
"Can't you go there?", but "Can you not go there?"

But "cannot" is in a class all of of its own. I don't think the fact that we can't/cannot/can not use it in question form has any bearing on which is better in positive statements.

As for your other point, it is fine to use "could" as the past of "can" when talking about general ability in the past - "At the age of four he could already read and write", but not to talk about ability on a a specific occasion - "I locked myself out last night, but was able to get in through a back window" - NOT - "I could get in through a back window". In negatives though, "couldn't" works for both general and specific ability in the past - "I couldn't find my keys last night".

Modals don't really have tense, but on certain occasions, such as reported speech, four modals can act as the past of others, so: will>would, can>could, shall>should, may>might.

Incidentally my grammar books warn against simply seeing "could" and "would" as the past of "can" and "will", as they also have several other functions, like for example, distancing - "Could you pass me the jam, please?"

@Skeeter Lewis - You might well prefer "were", and that's fine. But I don't for one minute go for this confusion argument.

In the article linked to above, Professor Pullum points out that the average native speaker knows about 5,000 verbs, in all of which the subjunctive is exactly the same as the indicative. There is one exception, "be", which is only different in two persons, 1st and 3rd singular. Why should there be this confusion with these two instances when there is no confusion with the other 4999, or with 2nd person singular and plural and 1st and 3rd person plural of "be"?

By your argument we could say:
"If they were rich, they would buy a new house" - they can't remember if they were rich
"If I worked there, I'd resign" - I can't remember if I worked there
Why are "If I was" and "If she/he was" so different?

In any case, I sincerely doubt there were many people thinking that all three candidates had had a problem with memory loss :).

@Kamran - my version would go something like:
Sara: Hello
Natasha: Is that Sara?
Sara: Yes, this is Sara (speaking).
Nat: Is that really you, Sara?
Sara: Yes, this really is me / Yes, of course it's me. Why wouldn't it be?

NB I think usually only the person talking says "speaking". And note how we use "this" and "that" and "you" and "me" rather than talking in the third person.

@Skeeter Lewis - there you are; we're agreed on something.

Just to confirm, backshifting is when we DO go back a tense,eg: "She said it was raining". If I say "She said it's raining", there's no backshifting, because I'm reporting in the same tense as the original direct speech. Backshifting includes the whole gamut of present to past, past simple (and present perfect) to past perfect, can to could, may to might etc:
Sara: "I wasn't able to do it, and I still can't" - Sara said that she hadn't been able to do it and that (at that time) she still couldn't".

And another article, by Professor of linguistics, Geoffrey Pullum, at The Chronicle of Higher Education - http://chronicle.com/blogs/linguafranca/2012/11/09/grammatical-relationship-counseling-needed/

If anyone is still following this, there's an interesting blog post (relevant to the original question) by Jan Freeman, ex of the Boston Globe at her blog - http://throwgrammarfromthetrain.blogspot.com/2012/11/fighting-off-were-wolves.html

@Skeeter Lewis - Hi. Although Sequence of tenses may be the standard term in traditional grammar, it's not one that's used much in my field, which is EFL/ESL. Probably the most popular British EFL reference guide, Practical English Usage, by Michael Swan (Oxford) , doesn't even list it in the index, and I can't remember ever having come across it in EFL course materials or grammar books. Instead we cover the same ground in several different ways - tenses in reported speech, tenses in conditionals and future time clauses, future in the past etc.

By the way, "The New Fowler's" also says (under reported speech) - "A change of tense is often involved". But as far as I can see in your first comment, you were saying that a change of tense was always necessary (except, now, for universal truths). Maybe I misunderstood.

Since this correspondence started I've been investigating the subject somewhat and there's not a lot about sequence of tenses on the net either, and what there is is a little confused. But I've found several other commentators (as well as the ones I listed above) who allow the present to be used for situations that are still true, for example:

"Backshift . . . is optional when what was said applies equally at the time of reporting - 'Benjamin said that he is/was coming over to watch television tonight.' ..." (Tom McArthur, Concise Oxford Companion to the English Language. Oxford University Press, 2005)

"A shift is not necessary if: the speaker is reporting something that is still true.
'Fred said he drives/drove a 1956 Belchfire Special.' "
(Ron Cowan, The Teacher's Grammar of English: A Course Book and Reference Guide. Cambridge University Press, 2008)

http://grammar.about.com/od/ab/g/Backshift.htm

So I'm sticking by my original comment; in the example given, we have a choice. On a lighter note, I also found this anecdote from the editor of the Wichita Eagle, courtesy of a journalism school:

“A man called the newspaper to say how upset he was about the Sunday story, 'Zoo swings into action to fix swaying bridge.' The call was from the man who fell from the bridge when it first opened. He said he was upset that the writer said he had a prosthetic arm. He is a veteran and still has that prosthetic arm. He wanted to know who her editors were and why she didn't check her facts. He was cussing a lot and threatened to cancel his subscription."

And the school comments - 'So, please note: “He said he has a prosthetic arm” is perfectly OK because we certainly don't want to lose subscribers. Seriously, the lesson here is to use common sense, which should always prevail.'

http://web.ku.edu/~edit/not.html

Incidentally, on the subject of tenses, I would have written - "He said he was upset that the writer had said he had a prosthetic arm", but never mind.