This clip comes from the webinar 'Communicative Learner-Centred Grammar' by Peter Lucantoni, broadcast by Cambridge English Teacher. Please note that video and audio quality has been reduced compared to the original broadcast, which also included chat boxes and other interactive features not visible in this recording. The full replay runs for 1 hour and is available at http://www.cambridgeenglishteacher.org/eventdetail/1130. This explores the topic in full detail and is free to play for Members. Learn more about Membership at http://bit.ly/CETMembership