Do you walk on a pavement or a sidewalk, turn on a tap or a faucet, change your baby’s nappy or diaper? Do you write to someone or write someone, look out of the window or look out the window? The latter are interesting, because though less obvious than basic differences of vocab, the American elision of the extra little prepositions so dear to the British can still affect the rhythm of a sentence.
See this blog post, which refers to differences between the American (Grove Press) and British (CBe) editions of the Agota Kristof trilogy. (For the record: the translation of The Notebook by Alan Sheridan, a Londoner, was Americanised for the US edition, then de-Americanised for the CBe edition; The Proof and The Third Lie were brought into English by two other translators, one British and one American, and some local changes were made to the versions published in the US before the CBe texts went to print.)
Then see this Tim Parks piece (also linked from the blog post referred to), in which he records his tussles with an American copy-editor over not just vocab but how to indicate time and temperature, and units of distance and currency, and the placing of certain words in a sentence, and not beginning a sentence with a number, etc.
The Harry Potter books were, apparently, ‘thoroughly’ Americanised (or -ized) for the US. Do they do this to Ishiguro? (Alan Bennett? Virginia Woolf? Dickens? Would we even think of reverse-doing this to Miranda July, Ben Lerner?) At one point when I was working for Faber I was paid to Anglicise a Paul Auster novel; for a later novel someone decided, sensibly, to just take the US setting, change the prelims a bit, slap a Faber logo on it, and not bother about that split infinitive.
I have some sympathy for the American copy-editor of Tim Parks. My first work in publishing, mid to late 1970s: I persuaded an editor to let me copy-edit a manuscript (about 18th-century Scottish bookbinders), then borrowed Judith Butcher’s Copy-editing from a library to learn how to do it. The usual UK guide for when to italicise and hyphenate and use caps and when not, how to punctuate direct speech, etc., is OUP’s New Hart’s Rules. US copy-editors have their equivalents. All of these gospels are more than useful; you cannot copy-edit without them (and copy-editing is as necessary as it is humdrum, by which I don’t mean to say it’s not a skill, or interesting, it is; and you can earn some money). But there is a category difference between changing double to single quotes, or unspaced em-dashes to spaced en-dashes, and the inserting ‘of’ in ‘I look out the window’.
Parks, wondering why ‘house style’ in the US is so ‘aggressively enforced’ – ‘to the point that when one rereads work one has written for The New Yorker it no longer seems like your voice at all’ – ends his piece thus: ‘Or could it be that the long American hegemony has bred an assumption that American formulations are inevitably global currency and should be universally imposed?’ Imperialism again, or still. If so, pointless; as much a rearguard action as was me being paid to Anglicise Paul Auster. The whole notion of any standard ‘American usage’ or ‘British usage’, if understood as applying to anything more than the decorative (single or double quote marks), is a bit barmy: even within these countries, writers write from north or south or west or east (D. H. Lawrence: ‘All childhoods are provincial’), and from very specific cultural backgrounds, and many not in their ‘mother tongue’; and many writers in English move from one side of the pond to the other, and absorb different street & speech rhythms that feed into their writing.
Among the several recent new translations of Madame Bovary, the Lydia Davis is presumably in US English, the Adam Thorpe in Brit English. Either is fine by me, as long they’re consistent within their own covers. It was a degree of consistency that I was aiming for when I fiddled a little with the translations of The Proof and The Third Lie. Though I still think you can tell that each of the books in the trilogy had a different translator.