You’re supposed to do that for any word where two consecutive vowels have a syllable break between them instead of forming a dipthong. Of course, most of the time it’s redundant because there’s only one cromulent word anyway and the reader can figure it out quickly enough without the umlaut.
I think "supposed to" is overstating it given that I've only ever seen it used by this one publication. To boot, I wouldn't pronounce the word they use it for, coordination, (in context, "piloting it demanded constant coordination") with a syllable break, either.
It’s true that most Americans are lazy and do not pay sufficient attention in school. Thus the observation of nuances such as this are becoming rarer every day.
Do you pronounce the “oo” in “coordination” the same way as you do in “bookkeeper”? Because that is a very weird mispronunciation. https://en.wiktionary.org/wiki/coordination
> The compact is far from perfect. It is vague about how countries should cooperate on many issues, such as border management and access to public services.
The New Yorker is famous for its commitment to unreality on this issue. It's only the New Yorker.
Rather than "You're supposed to...", it would be more accurate to say, "It was once a common convention—that has since mostly been abandoned and is retained as a general rule only in a small minority of publications, of which the New Yorker is the most notable—to..."
For this rule, the word I see most often is "naïve". I used to write it that way but now I use the simple spelling of "naive". The diaeresis emphasizes that "naive" does not rhyme with "dive", "five", "hive", "jive", etc.
> The diaeresis emphasizes that "naive" does not rhyme with "dive", "five", "hive", "jive", etc.
It can't emphasize that; there's nothing to suggest that "naive" would rhyme with those words. It emphasizes that it doesn't rhyme with "glaive" and "waive"...
