I just had such a telephone interview this one to go to International House Barcelona.
All I can say is that in my case, the interview only lasted 15 minutes, they just wanted to know that I'm not someone who looks at the floor all the time, can look people in the eye and that I had ability to pay!
We breezed through the pre-interview tasks and that was that.
The best advice I can offer you is just try to be relaxed and take a pause before answering any question, and have your pre-interview task to hand just in case they bother to ask you anything pertinent.
- For Teachers