Much information on this page is drawn from chapter 2 "Free Verse: Invisible Nets and Trellises" in Writing Poems by Robert Wallace, © 1982 by Robert Wallace.
Free verse is an open, organic form of poetry, written without an obvious meter or rhyme or rhyme scheme. The term is borrowed from the French words vers libre, meaning, of course, "verse liberated" or "freed verse."
Outstanding poets have praised and deprecated free verse. Rober Frost compared writing free verse to playing tennis without a net: it was too easy and without point, challenge or fun.
W. H. Auden describes the problem of writing free verse:
The poet who writes "free" verse is like Robinson Crusoe on his desert island: he must do all his cooking, laundry and darning for himself. In a few exceptional cases, this manly independence produces something original and impressive, but more often the result is squalor--dirty sheets on the unmade bed and empty bottles on the unswept floor.
So there are detractors of free verse. But there are also many who favor writing poetry in that form (or should I say formlessness?). The father of modern end-stopped free verse is Walt Whitman. Whitman rejected the traditional metrical patterns in favor of the free flowing form now called free verse. And many of us can see immediately why one might favor free verse. We have something important to say. We do not want to subjugate the perfect word in favor of some lesser word simply to meet the requirements of rhythm and rhyme. Our motto might be: "Choose the best possible word, the exactly expressive word, then use it, regardless of the consequences. We refuse to subjugate meaning to form." And so the debate rages on.
Free verse is frequently classified according to the type of verse line it uses. Since the lines are of no particular length, meter, or rhyme, those conventions will not work in describing free verse. The two types of free verse are:
In end-stopped free verse the line-breaks occur at syntactical or grammatical pauses or intervals. In other words, the individual lines usually end with some mark of punctuation, the comma or period.
In run-on free verse not even this convention is followed. The poet ends a line whenever and whereever he/she wishes. But the break should never be arbitrary. Effective use of run-on free verse requires thoughfulness. Breaking lines in such a way can emphasize certain words or ideas and can create a rhythm, though not a regular or predictable one. Run-on lines are also referred to as "enjambed" lines. The technique is called "enjambment."
So how can we know that a free verse poem is actually a poem? How is free verse different from simply chopped-up prose?
Those questions can best be answered with an analogy. Refer to your basic physics text. If we place a certain quanity of a gas in a container, it has a certain pressure. If we squeeze all of those molecules into a smaller container, we create greater pressure and greater density.
In the same way, if an author writes 100,000 words in his latest novel, he could capture a great deal of meaning. His prose could take him about anywhere he wanted to go. But if he tried to capture all that same meaning in an 4500 word short story, he would have to be very careful, wouldn't he? And to reduce all that meaning or observation of life into a single short poem would require the ultimate skill. The "meaning density" would naturally go up. That is the fundamental difference between prose and poetry. Prose can linger, take side trips, if desired, relax a while. Poetry attempting to capture the same meaning must be extremely focused, intense, and energetic.
In the end, you will find that free verse is not free at all. It will cost you something to write quality free verse that touches others. It will cost you time, energy, focus, and often, many revisions. Free verse is not necessarily easier, when written well.
As T. S. Eliot says: "No vers is libre for the man who wants to do a good job."