(Background for those that don't know ) Okay, so my son does school at home under my supervision and it gets sent to his proper teacher who marks it all and then it gets sent back.

Yesterday he got some work back and in a story he had written they corrected his spelling of 'gaol'. While I know it's not the most common spelling of it I did, at the time, explain to him that there is a couple of ways to do it and just selected that one to put in and now it's come back, mark by a sub-teacher, as mis-spelled. It has slightly peeved me as I don't think it's wrong unless I missed something?

Has 'gaol' completely gone out of favour?
I need this teacher to go and correct the Old Melbourne Gaol signs

I almost want to send it back and correct her

Looking here, that is still a correct spelling. Marked by a substitute, maybe his teacher can't spell!

I read somewhere around (more than likely FT but maybe one of my many books on English) that gaol was the earlier spelling, and had become phoneticised to jail, by the time I arrived both were standard spellings but gaol considered the academic/official one. If I can find the book I'll add the specifics here but pretty sure that was why one seemed to take over from the other.

I always thought the same as David - gaol is the older spelling, probably BE, and the Americans decided that jail was easier to cope with, or simply made more sense.

Perhaps you could introduce the sub-teacher to a bit of Wilde's poetry: The Ballad of Reading Gaol.

Satguru and Lesley are right. Spellings with an initial g and j are noted in medieval English in the Oxford English Dictionary, but gaol used to be the usual literary and official form in Britain, with jail replacing it in popular use.

The word is virtually obsolete in official British use nowadays: the establishment where Wilde served part of his sentence is now officially Her Majesty's Prison, Reading (abbreviated to HMP Reading). Circuit judges are still, I believe, officially termed Her Majesty's Justices of Oyer and Terminer and General Gaol Delivery, but you won't normally see or hear the word in official documents or speeches.

The Oxford English Dictionary was already preferring jail in 1900 or thereabouts, and it's undoubtedly the usual form here in Britain. However, dictionaries still give both forms, and so I don't see any reason why Conor shouldn't write gaol.

Yes, I do believe that 'gaol' is the spelling formerly used in British English and is still, technically, correct. I would say, however, that language is constantly evolving and, arguably, it is popular usage which defines whether a word is correct or not. I would say that, technically, 'gaol' is a correct spelling, regardless of the fact that my spell-checker doesn't recognise it, but seeing as the point of language is to convey your ideas to others, it would seem to make sense to use the standardised, generally accepted spelling. I could easily say 'verily I do declare that I find myself in a state of acute desire for some form of foodstuff', but it just seems to make sense to say 'I'm hungry', given that that is what most people will understand . It's also considerably easier, but then so is the spelling 'jail' and that isn't really the point:).

Edit: Also, I'm with Lesley, 'The Ballad of Reading Gaol' is a brilliant poem (sorry for the minor distraction:).)

How ridiculous! Conor is 7 years old . The word 'gaol' is perfectly correct. I am so sorry for children with stupid, ignorant teachers who seem to want to undermine their efforts and zap their confidence. Silly woman!

Have a look at this site - list of Australian prisons. You will not see the word 'jail' at all. Most are now called the very PC 'correctional centres', but quite a few of the older references are to 'gaols'.

'Jail' is a purely American spelling. It is becoming part of the Australian language, but I would not use it. Old habits die hard.

ozzz2002 is correct, that's how we spell it in downhere. I was taught it's the BE v American English spelling thingamajig
Here's an aerial view of Silverwater Gaol, here in Sydney: http://www.airviewonline.com.au/photos/0801-1001-07/Silverwater-Gaol-Close-Up-NSW
Click on the picture for a close-up view

The aerial photo may have been used for a prison escape back in 1999, using a helicopter!
http://www.abc.net.au/news/newsitems/200206/s588018.htm

Teachers are not necessarily very well educated.

A favourite short story I read many years ago hinges on the misspelling of gaol as "goal" - the football player almost was unjustly arrested for the murder, until our hero stepped in and cleared it up.

Well I would always write it as 'gaol', and I think I would send a friendly note back to the sub to ask them why they 'preferred' Conor to use the 'jail' form of the word?