I've read a few historical romances lately--I'm quite partial to them -- but my enjoyment has been spoiled by American anachronsims in the language. I'm sure the US authors and their editors don't even notice, but I do!
It grates on me when a young lady in supposedly Regency England says "It's time to go wash up." NO!!! Can you imagine Jane Eyre saying that to her charge? I don't think so. And replying to the query "How are you today?" with "I'm fine."
The weird thing is in many other respects the authors go to great lengths to use formal language and terminology relevant to the setting.