If you are using a mobile just unnable the "system language" and enable all languagens you want. In Android if give a button with a globle and the name of the language in the space bar. Once the right language is on you just need keep pressing the key until it show the option.
But not here in discussions, I use the International keyboard which is easy to install and learn. Be sure to scroll past the support has ended. It is clearly indicated how to set it up and further down, how to create the accented letters. I probably will add the Swedish keyboard also unless the Danish already has all that I need. Alt + 0229 works as well for me, but I think that letter is also in Danish.
Say is it just me or do the verbs not conjugate like in Danish?
That's if you use it with dead keys. Many people don't, because they find them annoying. (To get normal ", you have to type a space afterwards.) I think the variant without dead keys is usually the default nowadays.
With US-International without dead keys: Right-Alt-q = ä, Right-Alt-p = ö, Right-Alt-w = å. (So the right Alt key has the AltGr function. The left Alt key still has its normal function. This is also how the two keys work in most keyboard layouts other than the US one.)
What's the difference between a neutral gender and a common gender? (Looking at Arnauti's answer below.) How do I know which gender apple is? Does Swedish have male and female objects like Latin languages (Spanish, French)?