The only one I can think of is 'breakable' - where the active (ergative) meaning - it can easily break - is just as likely as the passive one - can easily be broken. But I can't find any other ergative verbs apart from 'chang' and 'vary' where the same is true.

I was thinking of flammable, but that's from a noun (although that originally came from a Latin verb).

@jayles - I think quite a few Brits do it as well. At the British National Corpus it's 159 'an historic' to 126 'a historic', but of course pronunciation doesn't come into play there. Funnily enough I've just been looking at something else in a book called 'An Historical Syntax of the English Language', published in 1963.

Even with a silent H, it seems to me somewhat old-fashioned now, and no doubt it and horrific (50 'a' to 25 'an' at the BNC) will eventually go the way of 'hotel' (754 'a' to 76 'an' at the BNC).

Couldn't resist it - I wrote this three years or so ago - http://random-idea-english.blogspot.com/2011/01/how-i-ngrammed-historic-occasion.html

I've just noticed this from dogreed way back in 2010:

' The words "everyone" and "everybody" are not entirely interchangeable. For example, the phrase "God bless us, everyone" is generally taken to mean "God bless us all," while the phrase "God bless us, everybody" might be taken to mean "hey y'all, God bless us." '

Except that the standard phrase isn't "God bless us, everyone", but "God bless us, every one".

http://books.google.com/ngrams/graph?content=God+bless+us+everyone%2CGod+bless+us+every+one&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1%3B%2CGod%20bless%20us%20everyone%3B%2Cc0%3B.t1%3B%2CGod%20bless%20us%20every%20one%3B%2Cc0

As has been pointed out by douglas.bryant and others, "everyone" is not the same as "every one".

But this seems to be a common mistake: the best-known instance of the "God bless us" quote is no doubt that from Dicken's 'A Christmas Carol'. If Tiny Tim had indeed said "God bless us, everyone!", as is falsely quoted in Wikipedia and elsewhere, his meaning would in fact have been rather like a southerner's "hey y'all, God bless us." - the one dogreed gives to "everybody".

But in fact, what Tiny Tim actually says was "God bless us, every one!", meaning something like "God bless us all," or "God bless us, each and every one of us" and which is repeated on the last page.

http://books.google.pl/books?id=MlMHAAAAQAAJ&printsec=frontcover&dq=a+christmas+carol&hl=en&sa=X&ei=ONkOVIOdI-fnyQO7zYHQCA&redir_esc=y#v=snippet&q=%22god%20bless%20us%20every%20one%22&f=false

There's a discussion about this common misquotation, which goes back at least to the 1870s, here:

http://books.google.pl/books?id=Jldiza39QrcC&pg=PA54&dq=%22god+bless+us+everyone%22&hl=en&sa=X&ei=cdEOVIXJKMu6ygOB8YDgDw&redir_esc=y#v=onepage&q=%22god%20bless%20us%20everyone%22&f=false

So it's back to the drawing board for that one. They are interchangeable. From Oxford Online:

Everyone = Every person: "everyone needs time to unwind."
Everybody = Every person: "everybody agrees with his views."

I see absolutely no subtle difference of meaning between those two example sentences.

douglas.bryant has already mentioned Fowler. In the entry on 'everyone, everybody' in The Merriam Webster Dictionary of English Usage, the only discussion is about what pronoun usually follows them - there is absolutely nothing about any possible difference in meaning or shade.

Look up 'everybody' in most dictionaries and usage books and they simply refer you to 'everyone'. If there were these differences people are talking about here, why do no dictionaries or usage books refer to them, I wonder? Why are there no usage notes explaining the difference?

@Phil Woodford - that sounds pretty much like this definition from Oxford Dictionaries Online:

"(chiefly North American) Seek to establish communication with someone, with the aim of offering or obtaining assistance or cooperation:

"his style was to reach out all the time, especially to members of his own party anyone in need of assistance should reach out to the authorities as soon as possible" '

Admittedly this is slightly different from the meaning I'm used to, but what both Hairy Scot and I have noticed is that 'reach out' is being used to simply mean 'contact' as in these examples form various tech sites:

‘If you would like any other suggestions or need help with transitioning your current Google Reader RSS feeds, please reach out to a Library’

‘Wired has also reached out to Google for additional comment.’

‘If you want to follow up, feel free to reach out to me by phone.’

@Sophie - I'm all for simpler English, but the passive should be regarded in the same way as any other construction - not get the blanket (and unthinking) disapproval it does in certain quarters.

It is very easy to be long-winded using only the active voice, and it is equally possible to be informal using the passive. Which is the more long-winded here, I wonder:

The company have dismissed him.
He's been sacked.

The passive is especially useful in English, where we don't have reflexive verbs, and for information packaging - starting a sentence with given, known information and putting important new information to the end (end weighting). This is what might happen if we couldn't use the passive:

"This is a picture of Canterbury Cathedral. Augustine founded it in 597 and various people rebuilt it between 1070 and 1077 after a fire destroyed it in 1067, the year after William of Normandy conquered England. Builders greatly enlarged the east end of the cathedral at the beginning of the twelfth century, and others largely rebuilt it in the Gothic style following another fire in 1174.

The cathedral is especially famous for the story of Thomas Becket, the archbishop who two knights murdered in the cathedral in 1170. Pilgrims used to visit his shrine, which builders placed in the Trinity Chapel, above his grave. Somebody removed the shrine in 1538, when Henry VIII summoned the dead saint to court to face charges of treason. Having failed to appear, they found him guilty in his absence and they confiscated the treasures of his shrine , and carried them away in two coffers and twenty-six carts"

(Adapted from Wikipedia with all passive verbs changed to active. - check the original to see how useful the passive is) - http://en.wikipedia.org/wiki/Canterbury_Cathedral

Here are some non-formal (and easy to understand, plain English) examples of the passive (from a blog post I wrote some time ago):

Apparently he was born in Hungary.
They were married in the local church.
It's supposed to be a genuine Rolex, but I have my doubts.
Do you know his first book was published when he was only 15. Amazing!
Peter's flight has been delayed because of some strike or other.
It's a shame the youth club was so badly damaged in last year's fire.
We came by bus because the car's being serviced today.
The report? The final version is being typed up as we speak.
He was had up for speeding twice last year.

And some even less formal examples:

Three quid for a coffee! You've been done there, mate!
Would you believe it! I've just been given the heave-ho. Again!
Late again! You're fired!
I've had enough of being screwed around like this.
Some ref he is! We were robbed!
Don't tell me you fell for that email scam. You're so easily had!
I've been tweeted three times this week. And 'liked' on Facebook.
Like I was so not taken in by his smarmy charm!
So I use the Passive sometimes! Am I bothered?

And then there's the 'get' passive:

She got caught cheating.
We got soaked in the rain yesterday.
He got arrested for fraud.

@jayles - I've finally finished my (rather long and detailed) take on 'while' and 'whereas', and concession in general:

http://random-idea-english.blogspot.com/2014/08/exploring-concession-and-contrast.html

Yes, I'd go along with your first paragraph. I think the 'inasmuch as' meaning of 'whereas' is specific to legal English, and I've ignored it. It seems that 'whereas' is the most restricted, and should always express some sort of contrast, but that can sometimes include an element of concession:

'Whereas the city spent over $1 billion on its museums and stadium, it failed to look after its schools. ' - A city that spends a lot on its museums might be expected to look after its schools

My info about exams is slightly different:

CEF C1, CAE, IELTS 7.5
CEF C2, CPE, IELTS 9

Another way to look at it: Cambridge say that 'Holders of Cambridge English: Advanced (CAE)
display similar language ability to candidates who have an IELTS score of 6.5 to 8.0, and they give these equivalents for CAE (not CPE)

IELTS
7.0 - 67% - Grade C
7.5 - 74% - Grade B
8.0 - 80% - Grade A
8.5 - 87%
9.0 - 93%

http://www.cambridgeenglish.org/images/28894-cae-comparing-scores.pdf

And Academic IELTS is only 'Academic' in two of the papers, Reading and Writing. I don't think Speaking and Listening are that dissimilar from CAE and CPE. And now that CAE is amalgamating Use of English with Reading, I think they'll be even closer. I'm using IELTS materials with some students, and I don't see a huge difference.

You were doing so well until you got to Q - Colquhoun Ok, but Mosquito and Tequila? I don't think a K sound quite counts as silent. But you know what they say about pride!

As for your Vs, do family names (however noble) and Slavic first names really count?

And if you can count Milngavie, we could probably do the whole alphabet with Scottish place names (I know, double consonants and dipthongs probably don't count):

A - RaAsay, BreAkish, MurrAyfield, AVoch ( /ˈɔːx/ - Highland)
B - St Combs (Fraserburgh), TomB of the Eagles (Orkney), LamB Island (Forth)
C - GreenoCk, BuCkie, LossiEmouth, WiCk, BallaChulish (pronounced h, not Scottish ch)
CK - CoCKburnspath
D - FinDochty (/ˈfɪnɛxti/), KirKcuDbriGHT ( /kərˈkuːbri/)
E - IrvinE, KintyrE, PeeblEs, DrymEn, FrEuchie
F - MacdufF, CriefF, HaLFpenny cottage (Invermoriston), Ha'penny bridge, Kelvin (cheating)
G - ?
GH - Bight of Mousland (Orkney), Broughty Ferry, GiGHa ( /ˈɡiːə/)
H -EaglesHam, Lairig GHru, Orchid Place (Uddingston)
I - EdInburgh (local pronunciation - Ed'nbru), GlamIs, InglIston, EIlEan Donan, PennycuIck
J - ?
K - KirKcuDbriGHT ( /kərˈkuːbri/)
L - KirkcaLdy, ( /kərˈkɔːdi/), KilmalcoLm, PetercuLter, GlenaLmond, KilmalcoLm, TillicouLtry
M - KildrumMy
N - KilNcadzow ( /kɪlˈkeɪɡeɪ/), MilNgaVie ( /məlˈɡaɪ/)
O - Castle DOuglas, CarnOustie
P - CamPbeltown
Q - CoLQUhoun Park (Bearsden) (thanks for that one)
R - CambusbarRon, RAVenstruTHER (/ˈrɛnstri/) - otherwise Rs very much not silent in Scottish
S - WemysS, ISle of Skye, ISlay, hundreds of iSlands
T - ShotTs, Port CharlotTe
TH - StraTHaven ( /ˈstreɪvən/ ), MeTHven, RuthVen ( /ˈrɪvən/)
U - GlenmUick
V - MilNgaVie ( /məlˈɡaɪ/), AVoch ( /ˈɔːx/ Highland), RAVenstruTHER (/ˈrɛnstri/)
W - HaWick (/ˈhɔɪk/)
X -
Y - WemYsS Bay (/ˈwiːmz/), ISlaY ( /ˈaɪlə/)
Z - Culzean, Dalrulzian

Well, near as damn it.

At last I've found at least one source that suggests that 'while' can be used in either position for contrast, but only in first position when used concessively : the OALD:

used to contrast two things
While Tom's very good at science, his brother is absolutely hopeless.
Some people work better to music while others do not.

(used at the beginning of a sentence) although; despite the fact that…
While I am willing to help, I do not have much time available.