Teaching Idioms According to Webster?s Dictionary an
 According to Webster's Dictionary an idiom is 'an expression whose  meaning cannot be predicted from the usual meaning of its  constituent elements.'  I also like the definition of T.C. Cooper's  that 'An idiom can have a literal meaning, but its alternate,  figurative meaning must be understood metaphorically.'  In the last  week, since choosing 'idioms' as a subject for this paper, I have  been particularly aware of how many of these phrases are used in  everyday speech -' 'It's a piece of cake,' 'I'm fed up!' 'It's  raining cats and dogs,' 'Let sleeping dogs lie.'  These are enough  to make a student who has consulted an English dictionary shake his  head and say, 'I can't make heads or tails of what these phrases  mean,' which, of course, he cannot do until he has been taught the  actual rather than the literal meaning.
It occurs to me that a student with advanced skills would  need and want to learn idioms in order to better his comprehension  of the English language as well as his ability to speak fluently.  I  also believe that students on a lower level would enjoy learning an  occasional idiom because these phrases make the English language  more colorful and unique.  (However, studies have shown that  children up to the age of nine tend to interpret idioms quite  literally, thus attempting to teach them to young children would  likely result in confusion and misunderstanding ).    
 With this need to learn idioms comes the challenge of teaching  phrases whose meaning can only be known through conventional use.    A good way to begin would be an explanation to students that idioms  at first seem to make no sense and often are learned in the same way  new vocabulary words are learned.  Teaching the history of how an  idiom came into common usage is also helpful to students and may  provide clues to its present usage.  Students can relate to the  concept of idioms, when they explore the use of idioms in their own  language.  For example, in a Spanish language class I once took, it   seemed odd to me that the phrase 'you're pulling my hair' meant  you're kidding me until one of the students realized that in the  English language the idiom 'You're pulling my leg' had the same  meaning.   Teaching idioms can be interesting in that they would  easily lead to discussion about figurative language and why they are  used in speech and writing.  There should also be a word of caution  introduced so that students understand that idioms are usually used  in social situations, but when more formal language is required,  there are usually more appropriate language choices.   
In teaching idioms, the teacher should begin by choosing idioms that  are frequently encountered so that students have opportunities to  hear, read and use the expressions.  It is also important to choose  idioms that do not involve difficult vocabulary and grammar.   Students should also be initially introduced to idioms which have  transparent figurative meanings. 
Along with learning about idioms, students can be introduced to  metaphors and similes which also provide an increased ability to  express ideas and thoughts.   Being able to understand and use more  figurative language adds an interesting and colorful element to a  student's communication skills.   I hope one day to be able to teach  English to students with other language skills.  If I am fortunate  enough to do this, I will be sure to at least introduce my students  to idioms because they are fun, somehow make English more  approachable (less formal, anyway), and add a valuable dimension to  students' skills in English communication. 
Sources:
On line web sites:  International Reading Association - Read Write  Think:  Lesson Plan.          Figurative Language:  Teaching Idioms,  Abisamra, Nada, American                 University of Beirut.
How English Works, Swan, Michael and Walter Catherine Oxford  University Press, 2004.
Mary Beth Harris, a teacher at Tampa Preparatory School and personal  friend



