Why can I only submit answers in my native language?

This is probably due to one of the following reasons:

1) You don't have input language support installed. In order to input characters not used in your native tongue, you need an input manager like iBus or SCIM installed.

2) You don't have the proper locale/language pack for your input manager installed.

3) You forgot to turn on your input manager or switch to the correct input language.

4) You didn't change the input language in Vocab Builder. From the client's main window, click 'Preferences' and then select the language you wish to input your answer in (the unselected language will be the display language).