Michal Kazimierczak
4 min 
You’ve probably seen those two little dots that sometimes appear over the letter “u” in words like pingüino or cigüeña. That spelling mark is called a diaeresis (also known in Spanish as crema or cremilla, although these names are less common). Even though it’s small and often goes unnoticed, the diaeresis plays a very important role in Spanish pronunciation and correct spelling. In this article we’ll discover what it is, what it’s for, how it’s used, and some curiosities that will show you it’s not a mystery or an enemy at all, but a great ally.
What is the diaeresis?
According to the dictionary of the Royal Spanish Academy (RAE), the diaeresis is a spelling mark made up of two horizontal dots (¨) placed over a vowel, mainly over the letter “u”, to indicate that it must be pronounced when it would normally be silent. This happens in the groups gue and gui.
For example, think of the word guerra. Even though you see the “u”, you don’t pronounce it: it is /ge-rra/. However, in pingüino, the diaeresis over the “u” indicates that you must pronounce it: /pin-gwi-no/. This is key to avoiding confusion when reading or speaking.
The diaeresis also has another, more poetic and less common use: to indicate a hiatus in poetry. In this case, it is used to break a diphthong (two vowels that are normally pronounced together in the same syllable) so they are pronounced in separate syllables. For example, in words like vïuda or süave, the diaeresis separates the vowels for metrical purposes in poetry.
When is the diaeresis used?
In Spanish, the diaeresis is used exclusively to indicate that the vowel “u” is pronounced in the groups gue and gui when it would otherwise be silent.
Key rule:
- The diaeresis (¨) is placed over the “u” in gue and gui to make the “u” pronounced.
Examples: pingüino, cigüeña, vergüenza, antigüedad. - It is not used in gua and guo because in those cases the “u” is naturally pronounced.
Examples: agua, guapo, guion.
The diaeresis is never used on other vowels in this context.
The diaeresis in poetry: a help for meter
Although very uncommon today, in poetry the diaeresis is used to show that two vowels which normally form a diphthong should be pronounced separately, creating a hiatus.
For example, vïuda would be pronounced vi-u-da instead of viu-da. This helps maintain the correct number of syllables in a verse.
Another classic example is süave, read as sü-a-ve.
This use is now rare in everyday language but remains useful in traditional poetry.
How is the diaeresis written correctly?
- The diaeresis is a separate mark from the accent (tilde). If the vowel also carries an accent, both marks can appear.
- A common mistake is using it in words where it does not belong, such as paragüas. The correct form is paraguas (no diaeresis).
- It is only used in gue and gui when needed.
Curiosities about the diaeresis
• In other languages like German or French, the diaeresis has different functions, but in Spanish it is mainly used for “u” pronunciation in gue/gui and poetic separation.
• In Catalan, it is also used to separate vowels, as in veïna.
• The word “diaeresis” comes from Greek and means “separation”.
• It also appears in some foreign names adapted into Spanish, like Chloë or Brontë.
Common mistakes
- Using it where it shouldn’t be (like guion or gualda).
- Confusing it with the accent mark.
- Omitting it in formal writing where it is required.
Why is it important?
Knowing how to use the diaeresis correctly improves spelling, pronunciation, and clarity. It helps you communicate better and shows a stronger command of the language.
Examples to practice
pingüino, cigüeña, vergüenza, ambigüedad, antigüedad, lingüística, bilingüe
Poetic (rare): vïuda, süave
In summary
The diaeresis may look like a tiny sign, but it is very important for correct Spanish pronunciation and spelling. It ensures the “u” is pronounced in gue and gui, and in poetry it helps separate vowels for rhythm.
It’s a small detail that makes a big difference in how Spanish is read and spoken.
