How to change the language of your Debian system
* First, you have to set EnvironmentVariables such as LANG, LANGUAGE, LC_CTYPE, LC_MESSAGES to your local language. Usually LANG (or LC_ALL) is sufficient.
To do this, first open up the terminal and check what you have at present with the following command:
# env | grep LANG
* Second, you may also need to reconfigure your locales.
To do this, as root:
First: issue on a root terminal #export LANG=(two letter code for your language)_(two letter code for your country).UTF-8
For the Spanish language it would be:
# export LANG=es_ES.UTF-8
How do I know the 2 letter code for my language?
This page on wikipedia is helpful to help you determine this. You can see the fourth column on the table, for example Japanese will be 'ja'.
How do I know the 2 letter code for my country?
This website allows you to search this (remember to select Country Codes at the end). Upon searching Japan,you will get 'JP'.
So if you wanted to export Japanese, it would be ja_JP.UTF-8.
Second: reconfigure locales issuing the following command:
# dpkg-reconfigure locales
A window will ask you to select the languages (you select with SPACE) you want to have available. Choose your own.
Changes may not show immediately, a reboot will be needed.
How to change the language of KDE applications
Show available languages:( DebSearch:kde-l10n )
apt-cache search kde-l10n
Change the language:
apt-get install kde-l10n-thetwoletter (of your country)
as an example (for german 'de'utschland) :
apt-get install kde-l10n-de
Now you have your language in all KDE applications!