What Is a Diaeresis, and Why Do We Use It?

It's not an umlaut. It's a diaeresis.

Samantha Enslen, Writing for
3-minute read
Episode #782
The Quick And Dirty

The diaeresis is a little-used diacritical mark. It looks like two tiny dots above a letter. It sometimes appears in English over the second of two consecutive vowels, and it indicates that the second vowel is pronounced as a second syllable.

A listener named Al recently wrote in about our segment on the word “reenter.” Sometimes it’s written with a hyphen, and sometimes without.  

He suggested a third option: using the diaeresis. 

What is a diaeresis?

The diaeresis is a diacritical mark that looks like two little dots above a letter. It sometimes appears in English over the second of two consecutive vowels. If you’re familiar with German, you may have mistaken it for an umlaut since they look the same. The diaeresis’ job in English is to show that the second vowel is treated as a second syllable. Think of the long E in “Chloë,” for example, the second O in “coöperate,” or the I in “naïve.”

Diacritical marks in English

You’re probably thinking to yourself, “I’ve seen these words before, and they didn’t have any little dots in them.” 

That’s because the diaeresis, along with most diacritical marks, have fallen out of use in English. Take the word “hotel.” It came into English from French. It originally meant a mansion, and it originally had a pointy hat over the O; that is, an accent circumflex. That accent often appears in French over vowels after which an S used to appear. “Hôtel” used to be “hostel.” When the S went away over time, the circumflex over the O appeared. (1,2)

When “hôtel” came into English, it sometimes appeared with the accent, but that quickly disappeared. Have you ever seen “hotel” spelled with an accent? It’s rare.

Same with “résumé.” The Merriam-Webster dictionary shows the first reference of this word with an acute accent over both E’s. (An acute accent is a little dash tilted to the right.) However, plenty of people write the word "resume" without the accent marks, and three of the largest job portals on the web, LinkedIn, Monster, and Indeed, all avoid the accent marks.

And that make sense. Generally speaking, as foreign terms become naturalized into English, their accent marks fade away. That’s what’s happened with “hotel” and will likely happen with “résumé.” 

The origin of the diaeresis

That leads us back to the diaeresis. It had an important function back in the day. In fact, it was used in ancient Greece to separate a vowel at the start of a new word from a vowel at the end of a preceding word. That was important because Greek used to be written without any spaces between words! So that diaeresis—which comes from the Ancient Greek word for “division”—was really essential! (3)

While we’re talking about what words mean, “diacritical” from the name of the category that includes all these marks—the diaeresis, acute accent, circumflex, and so on—also comes from Greek, where it meant “something that separates or distinguishes,” which makes sense because all these marks distinguish their letters in some way. (2) 

The diaeresis may have been popular in ancient Greek, but today in English, it’s little loved, and hardly ever used. Except, perhaps, by our listener, and one noteworthy publication—“The New Yorker.”

The diaeresis in 'The New Yorker'

People regularly make fun of the magazine for this persnickety style choice. A recent article on the satirical site Clickhole announced that “The New Yorker” was going to “start putting two dots over every letter O, and no one can stop them.”

So why does “The New Yorker” insist on using the diaeresis? Their longtime copy editor Mary Norris has this to say: (4)

Basically, we have three options for these kinds of words: “cooperate,” “co-operate,” and “coöperate.” Back when the magazine was just getting started, someone decided that the first [could easily be] misread and the second was ridiculous, and adopted the diaeresis as the most elegant solution with the broadest application. 

Clearly, Al agrees. But will the diaeresis ever appear regularly in English again, outside of “The New Yorker”? Probably not. But stranger things have happened. We’d be naïve, with two dots above the I, to think otherwise.


  1. Garner, Bryan. Diacritical Marks. Garner’s Modern American English. Oxford University Press, 2016.
  2. Oxford English Dictionary, online edition. Oxford University Press. Diaresis, hotel, resume, diacritic (subscription required, accessed July 10, 2020).
  3. Owen, Jonathon. Umlauts, diaereses, and the New Yorker. Arrant Pedantry, accessed July 10, 2020.
  4. Norris, Mary. The Curse of the Diaresis. The New Yorker, April 26, 2012, accessed July 10, 2020.

Image courtesy of Shutterstock

About the Author

Samantha Enslen, Writing for Grammar Girl

Samantha Enslen is an award-winning writer who has worked in publishing for more than 20 years. She runs Dragonfly Editorial, an agency that provides copywriting, editing, and design for scientific, medical, technical, and corporate materials. Sam is the vice president of ACES, The Society for Editing, and is the managing editor of Tracking Changes, ACES' quarterly journal.