To check available locales you can use comand:

locale -a

To check current locale you can use comand:

locale

To temporary assign locale you can use command:

export LANG=en_US.utf8

To assign locale permanently you have to add bellowed command to file /etc/profile.

To run application with specific locale you can assign LANG environment variable value before application name. For example to run mc with russian locale you can type:

LANG=ru_RU.utf8 mc