Question: what is the name of the two dots over a vowel
Answer: The diaeresis ( UK : / daɪˈɪrɪsɪs / , US : / daɪˈɛrɪsɪs / dy - ERR - i - sis ; plural : diaereses ) , also spelled diæresis or dieresis and also known as the tréma ( also : trema ) or the umlaut , is a diacritical mark that consists of two dots (  ̈ ) placed over a letter , usually a vowel .