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Should you always use the accent in foreign words like “résumé”?
“Whereäs” as an alternative spelling of “whereas”
Is it spelt “naïve” or “naive”?
Merriam-Webster lists both spellings without any comment on validity / usage. The second variant seems to be the French original, and the other the "anglified" version.
Is there even a slight, maybe stylistic, difference?
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The stylistic difference is that writing naïve without the diaeresis comes off as rough and slip-shod, almost careless.
There is no other word in English whose pronunciation would work that way, which is quite different from how waive works. That means that the price of a diaeresis is adding a brand new rule or exception to English. That’s too high a price to pay.
A better spelling for those who can’t be bothered to write the diaeresis might be something nayeeve or even nigheve, but no one writes that.
