This power point goes over metaphors. It gives two different definitions as well as some examples. I taught metaphors after I had already taught similes and idioms so there is an informal assessment in the power point as well.
I always have a really good discussion during this power point as we go through the different examples. Talk about why it is a metaphor and what makes it a metaphor. Then you can have them change the metaphor to a simile to see if they really understand both. If some students don't really understand, then it is good for them to see the pictures and simply listen and learn from their classmates as well as you.
I also have a simile power point posted that comes before this lesson.