One activity I do with English Language Learners is teach several idioms; then have students use them in sentences of their own creation; and, finally, create literal posters illustrating what they have written.
So, let’s say they write “Please, keep it a secret – don’t let the cat out of the bag!” (note that they use the idiom correctly and include its meaning in the sentence). They would then draw a picture of a cat in a bag with someone talking to another person, along with their caption.
Then, they show it and share it verbally to the class. It can be a lot of fun.
Now, in addition to my drawing a simple model to show to students, I’ll be showing them this wonderful short video called “Confessions Of An Idiom.”
I’ll be adding this post to The Best Sites To Help ELL’s Learn Idioms & Slang.