The Modal Book
Modals, the bane of both ESL/EFL students and their teachers! They're all here,clearly explained with lots of examples, and then practiced in amusing written exercises.
14 units explore the form, meaning, and use of the American English modal verb system. Nothing could make modals easy, but this text is so focused and clear that it gives both students and teachers the courage to tackle these helping verbs, one semantic grouping at a time.
Here are a few examples:
Modals of Ability - Can, Be able
For fun, in the exercises Joe and Lisa imagine touring all around the world from one colorful culture and country to another, from Ecuador to Egypt to Thailand. There are 14 units visiting 14 countries. In the exercises, you can go shopping in Port Said, you ought to visit Kyoto, and you simply mustn't miss Montparnasse!
The Modal Book gives lots of fill-in-the-blanks workbook exercises (with the answers at the back of the book), but it will also serve as an easy-to-use reference that students will keep with them for years.
You won't be disappointed if you try The Modal Book.