In this post, I'd like to show you a way of presenting idiomatic language to your learners.
There are many ways to teach certain language features, some are more effective than others and not all of them work with all types of learners. But there's one I believe works for everybody, particularly with idiomatic language. I believe that visualising idioms, i.e. connecting an idiom with an image, helps to bridge the gap between the literal and the figurative meaning. So when teaching idioms, I show my students the picture first and draw their attention to the most salient aspects, and then slowly get to the metaphor the image represents. Later on I analyze the idiom with learners, i. e. we focus on grammar, words it consists of, concentrate on pronunciation, connotations, the degree of formality, etc.
Hang somebody out to dry.
This is a lesson plan for more advanced students but you can always adjust the content.
Tell your students they are going to learn a new idiom. Remind your students of what an idiom is. Elicit and/or give them plenty of examples they are already familiar with and provide the definition: an idiom cannot be understood from the individual meanings of its elements, and it's a combination of words that have a figurative meaning, which is separate from its literal definition.
Show your students the picture only (it's best if you can project it on the screen).
Get them to describe it in detail (in pairs or in groups).
Elicit words connected with the image and put them on the board.
Ask the SS if they can guess the idiom with the words they've got. Elicit answers. This stage can be fun, especially with more advanced students. They may come with sentences such as: I feel like a pair of shoes on a clothesline. :-)
Put the correct idiom Hang somebody out to dry on the board and discuss the literal meaning briefly.
Ask the Ss if they can guess the figurative meaning: to punish somebody for what they did. To help the SS, give them example sentences, such as: Once I find out who's vandalized my house, I swear I'll hang them out to dry. Alternatively, you can ask questions such as: How would you feel hanging out on a clothesline?Would it be a reward or a punishment for you? Thus you'll juxtapose the literal meaning with the figurative meaning. The funny part is always with somebody as opposed to something.
Get your Ss to discuss some questions in pairs/groups. Try to personalize the questions.
Have you ever hung someone out to dry for something? What did you do?
Would you like to hang somebody out to dry? What for?
Encourage your Ss to ask their own questions and share them with the class.
You may also want to discuss grammar, especially the irregular vs. regular form of the verb, the infinitive to-form, etc.
Finally, ask the Ss to come up with a similar idiom in their native language. This part is very interesting and challenging.
As a homework assignment (or in class), the students can answer the questions in writing.