Changing default text on display (Questions, Unanswered, etc)

Hi all,
I'd like to change texts such as "Questions", "Unanswered", etc when a question, list of questions or answers are displayed.

I checked the .mo and .po files: they only change plugin settings texts.

I am willing to edit plugin files, but I suspect there should be a lot of variables and such with "questions" in it. So, Find-Replace wont work.

Can someone please tell me where to look at exactly?

Thank you

ps: I'm planning to use the plugin as an evaluation form for some items (i.e. questions will be the items, and answers will be comments on those items, that can be voted up and down