When installing BF Survey Pro, you may get the following warning which is ok to ignore providing you get the "Install Component Success" message. Basically the warning just tells you that it can't install some of the language files, which is expected unless you have your Joomla site setup for all these languages. 

When installed, BF Survey Pro will add a language file to your Joomla Administrator.

For English /administrator/language/en-GB/en-GB.com_bfsurvey_pro.ini 

For Netherlands /administrator/language/nl-NL/nl-NL.com_bfsurvey_pro.ini

This will cause most of the text in the component to change to your language

And the text descriptions of the menu parameters will also change. The text used in the front end, for example the email subject "BF Survey Automated Notification" needs to be manually changed.

 If you want the text on the front end to automatically change, for example if you are using JoomFish to show your site in multiple languages, you will need to create the file /language/en-GB/en-GB.com_bfsurvey_pro.ini for each language of your site (you can copy the ones from /administrator/language/, then modify to suit).

Each line of your language file will be in the format:

ENGLISH TEXT=Translated text

eg.

RESULTS=Resultaten

If you would like your translation included in future versions of BF Survey, please contact us.