the repeating of words, phrases, lines, or stanzas.
Do you remember learning your multiplication tables? Writing and reciting them over and over until they were ingrained in your head? Have you ever noticed that most television commercials repeat their company’s name several times within a 30 second spot, whether in writing or out loud?
There’s a reason for that -- repetition emphasizes whatever it is that is repeated, making it stand out so the it becomes the most important part of whatever you’re reading/watching or learning.
When you repeat a word (or a line) in poetry, that appears to be more important than other parts of the poem. It can also affect the rhythm a poem and the way it sounds. Repeating individual sounds or groups of sounds can strengthen the rhythmic structure. Some forms of poetry use the repetition of whole lines as part of their structure. Pantoum, and villanelle are two examples of repeating poetry where the repetition is dictated by the form.
When using repetition, keep in mind that, though it may emphasize the line or word in question, to overuse this device can lead to a sense of monotony. This is especially true when the word or phrase being repeated is one that has little appeal to a reader to begin with. Be sure that the line or word is worthy of the special emphasis it will be receiving, otherwise, you may be writing an exercise in boredom.
“It is a cardinal sin to bore the reader.”
~ Larry Niven