If a word or phrase can not be translated it should not affect the survey it will simply show up in English.
Where can I find a list or phrases to translate?
When working on translations there are 3 files that might be helpful all can be found within schema.
MasterTranslationDocument2012 - contains a list of all phrases to translate
Translations.xml - contains translations of Phrases
Translations Static.xml - contains translations of static Phrases