First Conditional...an English teacher blogs.:

"I suppose it's natural that when you have so many classes you will encounter the odd eccentric along the way. One of my pre-intermediate classes has thrown up the strangest students I have ever encountered. ...I ask 'Does anybody have any questions before we go on?'

There's silence for a while, it looks like everyone has understood perfectly, then Carlos says 'Cheese is 'queso'?'

I reply, 'Erm....yes it is, Carlos. But do you understand the present perfect?'"

Irreverent tales from the classroom - this is definitely worth keeping an eye on...