Repetition

Definition: a portion of a poem in which a word, set of words, or phrases is repeated

Example: 

Because I do not hope to turn again
Because I do not hope
Because I do not hope to turn....

 Explanation: Repetition gives you more emphasis on the concept of the poem. Once you know what is being repeated, you can get a clue on what the poet wants you realize is the main idea. Also, repetition can lead you to the theme of the poem.