Not sure if this will work in Safari as old as 6.2, but try opening a new, blank Safari window, type something spelled incorrectly in the search bar and then (on the edit menu?) look for substitutions or similar and see if you can untick the option to autocorrect - text replacement.
Here's another 'might just help':
If you still have the "old" Pages (Pages '09, v4.3), you can designate parts of the text as being in different languages independently of the keyboard in use and hence get the appropriate spell-checker dictionary. Use the Inspector, Text->More and look for the 'Language' heading. This is something that seems to have disappeared in the current version (along with a number of other 'clever bits').
IIRC, Microsoft Word can also do this, though I would not wish that particular program on anyone ;-)
Thank you Mick, that works. And thank you Tony, so does that.
Word for Mac was on this machine when I got it, but its an absolute nightmare. One doesn't wish to criticise those noble public spirited chaps at Apple does one, for removing the good bits?
Mick Burrell 