This is a nice full lesson, all about how tell lies in English (and get away with it!).
Use with the ppt first and then worksheet. Last, students choose a role play scenario and act it out in English.
Also see this nice lesson about lying - 2 truths and a lie. Also, Liar, Liar. Pants On Fire - Using lies in the classroom. And this nice Pass the Paper game - Truth or Lie? Also students can read this book about White Lies on Gif Lingua Books.
I find these activities ver interesting as a way o introducing the book "We were liars"
Thanks Lola! It seems like lying (though bad) is a very basic human instinct.