Website material

Apart from teaching, I'm also working on English lesson material for my boss' language learning website.  I'm now up towards the end of the highest level.  Native speakers tend not to use formal grammar structures on a daily basis, so sometimes I have to teach myself the particular grammar point before using it in a lesson!  Today I'll continue with a lesson about cleft sentences.  What's a cleft sentence, you ask.  Well, you'll have to do my lesson to find out!