Have you ever read a historical novel and been pulled up short by instances of anachronistic vocabulary? Maybe I’m just a grouch (don’t answer that), but I’ve been known to shout at a book when I come across instances of characters using words and expressions which were out of vogue (or hadn’t even been invented) at the time the story takes place. Not that my shouting does any good…
Words, like everything else, go in and out of fashion. If you’re writing a period novel, the characters clearly need to speak in contemporaneous English, and when I say ‘period’ I don’t necessarily mean very long ago. Just a couple of carefully chosen words here and there can evoke a precise decade – or even year – effectively. Writers are naturally more conscious of this than most, and are usually particularly careful where slang is concerned, as it changes so quickly: no-one would let a fictional skinhead say ‘super’, any more than Little Lord Fauntleroy would have said ‘fab’, but words in other less obvious areas go in and out of fashion too, and this is where many of us occasionally come unstuck.