If you use KDE, you should open the System Settings window (aka Control Center, whatever it's called these days), from there locate keyboard settings and change the language that way - no writing is needed, you can click your way trough. If there are multiple keyboard layouts in a list, you can set one to be default, or if you don't need the others, remove them and leave only your preferred language in the list, so you don't accidentally switch it to something else.
There's a key combination that switches the layout between the selected layouts (configured in the settings mentioned above), in some cases I think it's left shift + left alt, but it probably depends on configuration; it's fairly easy to accidentally push those buttons and get a weird layout, so if you don't need several layouts, I suggest configuring the keyboard language settings so that only one language is available for switching.
The same applies for other desktop environments too, at least those I'm aware of where you can have multiple layouts.
Last edited by b0uncer; 12-18-2008 at 10:57 AM.