гугл сразу ответил:
You should be able to add Ukrainian in the KDE Control Center -> Regional & Accessibility -> Country/Region & Language -> Add Language -> Other -> Ukrainian. I assume here that you have kde3-i18n-uk already installed on your system.
However, if you want to keep English (or whatever) as the language of the KDE user interface, and to be able to switch to Ukrainian keyboard only for typing, then you should just add Ukrainian in KDE Control Center -> Regional & Accessibility -> Keyboard Layout
And if you don't use KDE, you can try to change settings of your x-server. Godd examples can be found here:
http://www.linux.org.ru/books/lor-fa...tml#x11-layout.