So it didn't really work - but you can get the gist - Contrast in first position - Dictionaries 2, The Guardian 6, The Telegraph 0 etc

So for example, at the Guardian there were 31 definite contrasts, 26 of them in 'trailing' clauses, as opposed to 8 ambiguous, all in leading position, and 5 definite concessives, 4 of them in leading position.

OK, thanks. As I understand it, IELTS Level 7 is about the same as CAE, so 8.5 must be pretty well Proficiency.

Incidentally, although there's quite a bit on while / whereas in Quirk et al - The Comprehensive Grammar of the English Language, I can't find anything on order - leading or trailing. Nor is there anything in the more recent Cambridge Grammar of the English Language, Hiuddleston, Pullum et al. And these are THE two most important reference grammars of the last half century or so.

However I did a bit of research on 'whereas' myself and came up with the following. With the ambiguous ones I lean more towards concession. What seems clear is that whereas is used more for direct contrast than concession, usually comparing the same feature of two different people, things or situations, etc: 'Italy is in the south of Europe whereas Sweden is in the north'. In this meaning it usually starts the second clause, whereas when it is used to signify concession, the concession clause usually comes first. The reason more examples are from the Guardian is simply that it has no limits; I now have to wait a month before I can look at anything at the Telegraph! I hope this table works.

Dictionaries Guardian Telegraph
Contrast 1st 2 6 0
Contrast 2nd 14 25 11

Ambiguous 1st 13 8 2
Ambiguous 2nd 1 0 1

Concessive 1st 1 4 0
Concessive 2nd 1 1 0

@jayles - sorry, you've lost me there. What are EAP and GRA? And trailing (contrast) clauses? I've tried googling all three, but without any success.

A bit off topic, but never mind. The literal translation of 'soy yo' may well be 'I am I', but that is meaningless in English and an idiomatic translation would be something more like 'it's me'. From various songs, with my efforts at translation:

Soy yo quien mira la lluvia - It's me who's looking at the rain / I'm the one looking at the rain
Alguien te amó y alguien soy yo - Someone loved you and that someone is me.
Y esta soy yo - And this is me
Soy yo, te lo digo a ti. - It's me, I'm telling you

@jayles - and I thank you. Sometime ago I started a post on contrast and concession. This might just goad me into doing a bit more research and finishing it.

Just a thought, but it occurs to me that while and whereas are acting as subordinators in concession clauses, but are more like coordinators in contrast clauses.

Let's agree on that. I've looked at example sentences from a dozen or so dictionaries, and I can't find much in the way of 'whereas' with a concessionary meaning starting a main clause either, although there are a couple of possibilities. Here are my suggested meanings:

1. whereas starting the second clause

= but/on the other hand:
Some of the studies show positive results, whereas others do not.
Nanjing has also in the past been the capital of China, whereas now Beijing has that role.
I like to go swimming whereas Sheila likes to sail.

=while on the contrary:
Doctors' salaries have risen substantially, whereas nurses' pay has actually fallen.
The old system was fairly complicated whereas the new system is really very simple.
You eat a massive plate of food for lunch, whereas I have just a sandwich.
Alma was always nice to people on the phone, whereas Kevin could be cheerfully impatient.
you treat the matter lightly, whereas I myself was never more serious
She's the one who is moving on whereas her parents are stuck with the story, are stuck in the past.
Negligence depends on a breach of duty, whereas contributory negligence does not.
One came forward immediately, whereas the others hung back.

=while:
Thus Mr Smith is now the respondent to this appeal, whereas Mr Clark was the claimant below.
He lived through his era, whereas so many of his friends died in racing accidents.

=although (?) / while on the contrary:
The desks have damaged the walls, whereas a more appropriate choice could have prevented such damage.

=although?/while:
We thought she was arrogant, whereas in fact she was just very shy.

2. whereas starting the first clause:

= although
Whereas knowledge can be acquired from books, skills must be learned through practice.
Whereas the city spent over $1 billion on its museums and stadium, it failed to look after its schools.

So in the dictionary examples, whereas seems to more commonly start the second clause, but with usually a meaning of simple contrast rather than concession. I don't think concession impossible, but it seems quite rare.

The Teacher's Grammar of English has the first (concession) clause starting with while or whereas, but nothing about the main clause. So until I can find where it was that suggested that whereas could start the main clause with the meaning of concession, I'll more or less go along with your idea that it works like while. In other words that they can both start the first clause, for both contrast or concession, but they usually only have the meaning of contrast when starting the main clause (I still think that Loch Ness example is OK - but it's hard to find evidence):

http://books.google.pl/books?id=WCCk829jmzUC&pg=PA555&lpg=PA555&dq=whereas+concession+efl&source=bl&ots=iILWz8jBgq&sig=dCIqbSKiuAObMWgWq9sXweyqeDg&hl=en&sa=X&ei=DffoU9vbJoSc0QXN-oCQDQ&redir_esc=y#v=onepage&q=whereas%20concession%20efl&f=false

@Hairy - I've only just seen your comment, and sorry, only three years late, but I have to disagree - It's major generals, not majors general, and general is a noun here, it's not an adjective - if anything it's major that is (a noun) acting as an adjective. Like a lieutenant general or a brigadier general, a major general is a class of general, so it's general that takes the plural.

"The four will be commissioned as Army major generals for an approximate two-year term while serving intermittently in this role." - Oxford Online

"Cromwell's Major-Generals: Godly Government During the English Revolution" - Christopher Durston

On the other hand, an attorney general is a grade of attorney, just as an adjutant general is a grade of adjutant. In these cases 'general' is indeed an adjective. So here it's the first word that takes the plural:

"These guidelines explain the general enforcement policy of the state and territorial attorneys general who comprise the National Association of Attorneys General. " - State antitrust practice and statutes

"that all the other adjutants general shall have the brevet" - US Congress 1839

It's easiest to see when you compare a major general and a sergeant major. The first is a kind of general (not a kind of major) and so it's general that is pluralised. The latter is a type of sergeant (also not a kind of major), so it's sergeant that takes the plural s. Major generals, but sergeants major.

"Uncommon Men: The Sergeants Major of the Marine Corps" - John C. Chapin - 2007
"United States Army Sergeants Major Academy, Fort Bliss, Texas"

@jayles:

I don't quite agree:

1. Not necessarily - "While roses are red, violets are blue" expresses a simple contrast, and could just as well be written "Roses are red, but violets are blue." There is no necessary idea of concession here that needs 'although'. But 'whereas' would fit.

"While my neighbour has a red car, I have a blue one" - 'Although' would be strange here, as just because my neighbour has a red car, there is no reason to expect that I would have a blue one too. So there is no element of expectations not being met, and so none of concession. A better comparison would be with "one the one hand ..., on the other ..." or a simple "but". Again 'whereas' would also fit. On the other hand, "My neighbour has a red car, while I have a blue one" is probably a more common construction (see dictionary examples below).

But:

"While we usually buy red cars, this time we've gone for a purple one" does express concession, and both 'although' and 'whereas'would fit here.

But I see now that you're discounting this type from 'best usage', although I'm not quite sure why. This is from Practical English Usage:

"While/whereas some languages have 30 or more different vowel sounds, others have five or less".

One thing however. When 'while' expresses simple contrast rather than concession, it does seem to come more often at the beginning of the second clause, at least if dictionary examples are anything to go by:

"Spain is increasing the size of its fishing fleet while ours is contracting." - Oxford Online
"He likes camping, while she prefers sailing." - Chambers
"The south of the country grows richer, while the north grows poorer." - Macmillan
"Schools in the north tend to be better equipped, while those in the south are relatively poor." - Longman
"Some people work better to music while others do not." - OALD
"He gets £50,000 a year while I get a meagre £20,000!" - Cambridge

Interestingly, Cambridge has three entries for 'while' as a conjunction: the usual time meaning, contrast (="but)", and concession (="although"). And in all those examples, 'while' could be replaced by 'but'. So I'm not sure why you discount f and g, as this seems to be the most common way of using 'while' to express contrast.

2. Granted

3. Granted - but that is simply my hunch.

4. I'm afraid I don't see much difference between 'where' and 'whereas' in clauses of contrast or concession, except for the proviso that 'where' is not used to start the second clause when expressing concession, and that 'whereas' is more formal.

5. No. 'Whereas' can come in the middle of a sentence to indicate concession, not only contrast.

"Some of the studies show positive results, whereas others do not." (OALD) - contrast = 'but'

"We thought she was arrogant, whereas in fact she was just very shy." (OALD) - concession = 'although'

I'm sure there are lots of women whose husbands love them who nevertheless put on weight. Concession suggests that the second fact should come as something of a surprise, given the earlier information - I just don't see that direct correlation between being loved and putting on weight. Sorry. But I'm not married, so perhaps I'm missing something.

As for 'best usage' I'm not so sure. I think it's more likely a matter of personal preference and perhaps of register, especially in the case of 'whereas'. But, as Garner points out, you have to be a bit careful with 'while' that it does not get confused with a temporal meaning, giving the example:

"Len Hickman delivered the opening statement, while Jim Bethell made the closing statement".

As regards 'whilst', in British English it is just a substitute for 'while', so is always possible instead of 'while', although sometimes seen as a bit formal or literary. It is hardly ever used, however, in American English.

As far as I can see, sentences a-i are fine. Here 'while' is used to express a simple contrast between two things - roses are red and violets are blue. When we are talking about simple contrast, either clause can begin with 'while' or 'whereas'.

Sentences j, k and l are about concession rather than simple contrast, and here we can only use 'while' at the beginning of the first clause (although 'whereas' can still be used in both positions), which is what you've in fact done. And although I'd probably use 'although', I think k, at least, is grammatical. I do have a logical problem with j and l, however.

j (l)- While (Whilst) I loved my first wife very much, she did in fact become fat. - I don't see the connection here - her becoming fat has nothing to do with my loving her - there is no concession that I can see.

On the other hand, put the other way round, as in k, the result is more logical.

I think we are more likely to use 'while/whereas' for concession when the two points are more closely related than in your example, although I can find nothing in usage books to back up that hunch:

"While/Whereas the Loch Ness Monster is probably a myth, many people believe in it."
"Although my wife became rather fat, I love her all the same."

And then of course there are also 'despite' and 'in spite of', when the grammatical construction is appropriate.

In A Dictionary of Modern English Usage, Bryan Garner reckons 'while' a more 'relaxed and conversational term than "although" or "whereas" ', but thinks it's fine in formal contexts as well.

http://books.google.pl/books?id=35dZpfMmxqsC&pg=PA931&dq=although+while+concession+garner&hl=en&sa=X&ei=1iDmU7iNCMeYO42bgNgK&redir_esc=y#v=onepage&q=although%20while%20concession%20garner&f=false

'Although, though', are by far the more common ways of expressing concession, with 'even though' also apparently beating 'while'.

http://books.google.com/ngrams/graph?content=Although+he+loved+her%2CThough+he+loved+her%2CEven+though+he+loved+her%2CWhile+he+loved+her%2CWhereas+he+loved+her&year_start=1800&year_end=2008&corpus=15&smoothing=3&share=&direct_url=t1%3B%2CAlthough%20he%20loved%20her%3B%2Cc0%3B.t1%3B%2CThough%20he%20loved%20her%3B%2Cc0%3B.t1%3B%2CEven%20though%20he%20loved%20her%3B%2Cc0%3B.t1%3B%2CWhile%20he%20loved%20her%3B%2Cc0

And this is even when 'while' includes examples meaning 'at the same time as', in these for example, where I don't think 'although' would work:

"She'd lied, she'd cheated, while he loved her with all his heart."

"While he loved her, there was no hope of loving anyone else"

Some examples from the first page of Google Books, where I think 'although' could be substituted for 'while' with no change in meaning, but where there is a strong relationship between the two statements:

"she wanted children and he didn't, plus, while he loved her, he also loved himself."

"... felt how much she needed him, and, while he loved her, he resented this. "

"Finally, he sat down and told her that, while he loved her deeply and regretted that they would not be able to play on the physical plane any more, he could not have her hanging around his apartment"

"While he loved her a great deal, Jane's husband found her more and more difficult to live"

"he made it clear that while he loved her and was deeply committed to her, he also knew how to get along without her."

"while he loved her dearly, he knew of or at least suspected, most of her problems—real—imagined—or pharmaceutically induced."

Incidentally, there has apparently been some resistance to 'while' being used with a non-temporal sense like this, but I think objections to this are few and far between nowadays. You can read a bit about it at GrammarGirl:

http://www.quickanddirtytips.com/education/grammar/although-versus-while

@looloo - there was a type of cheap café in Britain in the fifties and sixties, serving things like fried food more than coffee, as far as I remenber, which were indeed known by many people as 'kayfs'.