Different Words
The viva is a purposeful discussion or series of them: sparked by your thesis, made deeper by your contributions and aimed at providing enough evidence for your examiners to confirm that you’ve earned your PhD status.
What you and your examiners say helps to move the conversation along. Of course, different prompts and different responses mean different things.
A question has a different impact than a statement. An answer means something different to an opinion. A big general question is different to a finely-focussed small question about page 72. Saying “I don’t know” means something different to a three-minute monologue about something you do know.
Different does not mean better or worse. It’s just different.
Whatever your words, be clear. Be thoughtful. Take your time. Check the details.