In linguistics, umlaut, which is from the German “sound alteration”, is a sound change in which a vowel is pronounced more like a following vowel or semivowel. Umlaut is a form of assimilation[1], the process of one speech sound becoming more similar to a nearby sound. The diaeresis, also known as the trema, and the umlaut are two different diacritical marks[2] that (in modern usage) look alike. They both consist of two dots ¨ placed over a letter, usually a vowel.