I've been using Ubuntu for few days and I really like it, but I have a problem with my keyboard: I can't use the left Ctrl+left Alt combination to type special characters like in Windows.
How can I activate this combination?
Open Text entry
,mark input source and press on keyboard icon. You will see all characters available for particular input source.(As you can see not many options for English (US) layout but instead you can use English (US, alternative international) layout)
If you want to use additional keys open keyboard>shortcuts>typing and set a Compose key and Alternative characters key. The latter is used to write additional keys of present keyboard layout (My guess is that's what you've been looking for).
In this case I have set RCtrl as Alternative characters key. Note that you can set only one key for this and not a combo like LCtrl+Alt, which is by all means simpler. You can change the layout however suites you to gain missing keys, but I don't think you can rebind the way you want and not create further mess with your system.
The Compose key is used to write special characters(lets say it is AltGr):
AltGr+Shift then release followed by a+e will produce æ.
To write Unicode Characters press: Ctrl+Shift+u, you will get underline u then release and type the Unicode without the leading zeros, e. g.:
Ctrl+Shift+u followed by aeEnter will produce ®, or
Ctrl+Shift+u followed by1f44fEnter will produce 👏
You can use Character map to drag and drop any of the symbols you need.
Useful, but little old link.
Text entry
(on my screen) is not available on my keyboard.
Compose key
and Alternative Characters key
. The ... source
items gets "change mode" activated also by clicks on the LEFT COLUMN - which does NOT happen for those mentioned earlier.
On Ubuntu, you have to use AltGr.
This key is also the one you can/should use in Windows, but as Windows predates the AltGr key, they (still) treat AltGr and the combination Ctrl+Alt the same way (most of the time) whereas Ctrl+Alt is used for navigation under Ubuntu.