Idioms, are perhaps the most complex part of any language learning experience as they are culturally relevant and usually seem to make no logical sense whatsoever to those as outsiders. Competent understanding and usage of idioms in a foreign language truly shows you that you are well on your way to mastering the language, and are pretty confident already. I am spending my year abroad as an English language assistant in Spain and so chose to use the English Idioms book in a few of my lessons to see how it can be used and if in fact using it was a benefit to my lessons. I also, as a language student, studied the Spanish idioms book.