British English
Thank you, but..........
I may at last have found my way through to the solution, thanks to guidance from other contributors.
In the Language and Text Preference Pane, you must click Edit List, {thanks psychofreak missed it first time round,} under the <Drag languages into the order you prefer> list.
Because British English is not checked in the checkbox by default, so it is in the hidden section.
Having suffered Pages keeping random paragraphs as (American) English, despite Select All -----> British English, and only finding out later that the instruction is ignored, maybe.........
I'm logging off and restarting with everything crossed.
Sadly NO!
Pages still thinks meter is a unit of measurement and colour a typo, and my Pages Edit Menu, only has Spelling in it, with no options to select any language. {Not Spelling and Grammar xUKHCx. It has Proofreading instead of Grammar.}
Any further help would be appreciated, I've tried everything listed in this Rumour, and some of my own, I am beginning to think my version of Pages has bugs.