El Capitan - getting special character instead of normal ones

Which application are you using? I just tried it in Pages and Word and could not reproduce it

Also check  -> Sys Prefs - Keyboard - Text see if something of the sort is listed there

You have the international keyboard set up in the settings. I get the same results ÿ. It is like that so you can put an accent over the vowels. á é í ó ú. Or tilde over the ñ, or the double dots over other letters. It does more than that too. You simply need to setup a US Keyboard in Settings -> Keyboard -> Input Sources. My shortcut key (I think it is standard) is Command + space bar. Hold the command key after tapping the space bar, and it will give show you what keyboard you are using and allow you to select what keyboard you want. You can also set it to show in the menu bar by the clock. I hope that helps a little.

srmac777

Glad to help, and that it solved your problem.

srmac777