Concept questions

Help please

I am currently completing the online TEFL course with i-to-i, and even though I thought I understood English, I apparantly don't understand it at all!!! Like a previous post I am having difficulty reaching the required percentage mark in the concept questions part of the course. I realise that not all answers can be a useful concept, however, it seems to me that what I think is a useful concept question isn't!!

I am getting more and more confused by the minute, could anyone please give me a simple way in which to understand please.

Thanks

J