A pentina is a poem in which the same five words are repeated (each stanza) at the end of the line. Crafting such a poem means using the same words in different ways, so this is a good way to practice using words with multiple meanings or words that can be different parts of speech.
A common adage among writers is “show, don’t tell”. Writing in this way prompts students to think of different ways to express the same thing. Students will have to use expressions and imagery – like native speakers do in most situations – instead of being straightforward.