http://www.engvid.com You had your chance... but you lost it. Now you have the chance to learn how to talk about lost opportunity in English! Master the usage of the modals could, should, and would. Learn how native speakers use these three modals to talk about what they could have, would have, or should have done -- but didn't! Then take the quiz at http://www.engvid.com/could-would-should-modals/ .

원문출처 : http://www.youtube.com/watch?v=X2C8bMztpKI&feature=youtube_gdata