The answer is: PC (MS Word) ... Umlautletters are typed quickly and easily with one keystroke.. On the Macintosh U.S. keyboard (default setting), use key combinations with the Option key as listed below. You will see nothing happen on the screen until you release the Option key and type the desired letter under the diacritical mark you have chosen. For example, if you wish to type é, first type Opt-e, release, then e. For a capital Ü type Opt-u, release, then U (capital u).