A free online English lesson from Oxford Online English. You can see the full lesson (with text and exercises) here: http://www.oxfordonlineenglish.com/using-must-have-to-should
'Must', 'have to' and 'should' have similar meanings, but they can't be used in the same way. English learners often find it difficult to use these words correctly. In this lesson, you'll see what these words mean and how to use them correctly in English.
