I have used the United States-International keyboard layout for years to enter Irish Language accented letters (á,é,í,…) and occasionally German letters with umlauts. I have done this with dead keys: In this layout ‘, `, “, ~, and ^ are dead keys. Nothing happens until you type certain letters following the dead key, at which point the letter appears with the appropriate accent, umlaut, etc. This has worked very well for me. TIL that you can do much more with that layout. How to use the United States-International keyboard layout in Windows 7, in Windows Vista, and in Windows XP explains all of this. Using the Right-Alt key and the Right-Alt-key with the shift key let you enter all sorts of wonderful things, e.g. ß (for German), € (Euro), ¥ (Yen), þ, ð, ø, Ø, ©.
Some of you may know this, but I suspect the vast majority of Windows users, and a lot of Linux users, do not. The link above refers to older versions of Windows, but the layout works on Windows 10 and on Linux. The process of installing the keyboard will depend on your OS. Look for “keyboard layout” in the documentation.
Pingback: Rebuilding a Linux System | From Hilbert Space to Dilbert Space, and beyond