Before watching the video below, there is a vocabulary research exercise to complete. The words in this table are all used in the presentation, in one form or another. Using a good dictionary (there is a link on my ‘useful links page’) you should try to complete the table as completely as possible. Some words have all forms, others don’t.
Once you have completed the vocabulary research, you should watch the video once for overall comprehension.
Then, opening the gap fill exercise, watch it another two times trying to fill in the missing conditional sentences.
Gap fill questions: What if Questions
Gap fill answers: What if Answers
Thanks to Ted.com for the video and source text!