Can a poem have line with only one word?

Yes, a poem can have lines with only one word. This technique is often used to create emphasis or to break up the poem into distinct sections. For example, in the poem "The Raven" by Edgar Allan Poe, the lines "Nevermore" and "Quoth the Raven" are used to create a sense of mystery and suspense. Similarly, in the poem "Stopping by Woods on a Snowy Evening" by Robert Frost, the line "And miles to go before I sleep" is used to emphasize the speaker's journey and the distance he must still travel. One-word lines can also be used to create a sense of rhythm or to break up the monotony of a longer poem.