You will likely have noticed the letter ø in the Danish language - used for everything from the everyday greeting halløj to the clichéd 'hardest sentence to say in Danish', rød grød med fløde('red porridge with cream').
What you may not know is the little symbol's long and interesting history.
Use
In terms of pronunciation, ø tells you that this is not an 'o' with an 'o' sound, but a different vowel entirely (the Danish alphabet has 29 letters and nine vowels, with ø, å, æ and y in addition to the five you also get in English).
The letter sounds a little bit like the 'er' filler word you get in English, but shorter and more clipped. The name of the letter ø is pronounced as a short 'ooh'.
Although I dispute the notion that rød grød med flødeis the hardest sentence to pronounce in Danish, or even any more difficult than average, it does do a good job of demonstrating some different ø sounds.
In both rød and grød, the ø is very short, while flødewith the additional e on the end elongating the word means you can also stretch out the ø sound a bit.
Plenty of Danish words begin with ø, such as øst(east), ørn(eagle), øre(ear), økonomi(economy) and økologisk(organic). It's also a word all on its own: ø means island in Danish.
On the matter of filler words, 'um' appears a lot in Danish speech and is spelled as øhm.
Origins
Written Danish has undergone a lot of changes over the years, including a mid-20th century reform which saw the German-style capitalisation of nouns dropped and the letter å introduced in place of aa.
Ø, however, goes back a long way and has been used in the Danish alphabet since the 12th century, according to Sproget.dk .
This was a period during which the use of Latin letters completely took over from the Runic writing used by the Vikings. This means that, despite its very Scandinavian aesthetic, ø was actually invented by the Romans.
It is believed that the letter first emerged as a contraction of o and e, and you’ll sometimes see oe used as a substitute for ø (for example, if someone can’t get the Scandinavian keyboard to work on a borrowed computer, or with old, non-Danish typewriters).
You’ll also see the o-e contraction as a ligature (joining of letters) in French, where it appears as œ in words like bœuf (beef). The Danish word bøf, meaning burger patty, is pronounced identically.
Ø is not unique to Danish, either as a sound or as a letter itself. Both Norwegian and Faroese also use the letter, while the sound in Swedish is represented by ö. Note that Swedes write Öresund, while Danes write Øresund, and Danes quite often spell the Swedish city Malmö as Malmø.
In German, ö is a very close equivalent of ø but is not considered a separate letter. Instead the Umlaut (the two dots) are a diacritical mark used to indicate different pronunciation to a normal o.
Typing the ø
If you are using a Danish keyboard, you will find the ø two keys to the right of the L on the middle row (and one to the right of æ). Because of this, punctuation marks like colons and semi colons are arranged differently on a Danish keyboard.
If you are using a keyboard purchased in an Anglophone country, ø is a special character, but it can be found with shortcuts. For example, if you press and hold the o key on a Mac keyboard, you'll get the option to select ø (as well as œ, ö and a range of other o-related letters).