If you want to teach what English conversation is really about there's a website where you can download for free the pdf files of the student's book and teacher's book. It's an innovative approach that explains the rules of conversation and contains losts of activities (some use drama techniques) for students to practise their English, also looking at intonation and body language. It's simple and written in plain English. All the answers are in the teacher's book.
Here's the website: