I hope you're not under the impression that it's essential to ask questions at the interview , because it certainly is not. Only ask a question if it's something you simply must have answered before you can accept the job if offered - a deal breaker, in other words. The best answer (and I speak as a head who has interviewed many hundreds of NQT candidates) to the question 'And do you have any questions for us?' is ' No, thank you - I've had ample opportunity during my visit here to get all my questions answered.' I've had candidates talk themselves out of a job offer by producing lists of questions they could have asked during the tour of the school, meetings with other staff, etc, which they were under some bizarre illusion would impress the panel.