What Is an Umlaut?
In the case of the lowercasei, those two dots replace the single dot.
The umlaut diacritic marks appear on uppercase and lowercase vowels:
Many languages, including German, use umlauts.

A few of those languages have loanwords in English, which are words English borrowed from the other language.
For example, the French word, naive.
The popular ice cream company Haagen-Daz illustrates such usage.

Different Strokes for Different Platforms
Severalkeyboard shortcutsrender an umlaut from the keyboard, depending on the platform.
Windows Keyboard Shortcuts
On Windows PCs, enableNum Lock.
Windows Character Map
You need a numeric keypad to enter numeric codes.
The numbers at the top of the keyboard, above the alphabet, won’t work in this way.
PressWin+Rto open theRundialog box, then entercharmap.
Double-smack the character you want to copy so that it appears in theCharacters to copytext box.
The Windows character map is also a great way to learn which hotkeys produce different characters.
Mac Shortcuts and Character Viewer
On a Mac, press and hold theOptionkey while typing the letteru.
Then jot down the letter to which you want to add the umlaut.
The Character Viewer program in macOS is another way to access these special characters.
You’ll find it on almost every page on the web.
This string must not include any spaces between the characters.
In HTML, the characters with an umlaut might appear smaller than the surrounding text.
To make the text flow better, enlarge the font for those characters.
FAQ
Toadd accent markson Windows PCs, turn onNum Lock.
Next, hold down theAltkey while typing the corresponding number code on the numeric keypad.
You’ll create characters with acute accent marks.
Totype a tilde markon a Mac, PressOption+N, and then throw in the letter you want to accent.
(See linked article for specific number codes.)