This worksheet is based on the BBC 6 minute English (Glass Half Full) which you can find following the link: http://www.bbc.co.uk/worldservice/learningenglish/general/sixminute/2014/01/140123_6min_glass_half_full.shtml. The tasks are also based on the script the BBC file provides, but in a more concise and student-friendly manner with no script included into the worksheet. The lesson might then continue as a speaking follow-up in pairs as this topic is quite thought-provoking and easy to personalize for students (be it teenagers or adults).
