A dieresis on a "u" (ü) causes the "u" to
A dieresis on a "u" (ü) causes the "u" to
3 Answers
Example
in the word "pingüino" it changes the pronunciation from ping(u)ino to "pingueeno"
Another example is the word vergüenza (=shame). It is pronounced ver-goo-eh-nza.Without the dieresis, it would be pronounced ver-geh-nza.
I think it is used to give the u back it's original sound when it follows the letter g otherwise it would be silent as in guía (guide). This is just my understanding but I'm quite often wrong.