Thanks so much for your reply Lucy.
Just to clarify, I will be teaching the lesson to the interview panel as if they were students, not to an actual class.
My issue is that the lesson must be language focused and at a UI level whereas I have mainly taught lower level students or very advanced students. I have taught the occasional UI class and this is one of the areas I have looked at and the lesson went pretty well. I was just concerned as my colleague suggested maybe it was more of a functions class than a grammar class.
Thanks for the reassurance re present and past often being taught together. I thought this was the case!