Unlike prose, which wraps freely from paragraph to paragraph, poetry is written in lines, which break in definite spots selected by the poet. Because of this, the line is considered a unit of composition, an important factor influencing sound and meaning.
Some poets measure their lines by counting stresses, perhaps giving each line four beats and then breaking for a new line. Some poets count the number of syllables per line, disregarding stresses.
Others work with feet, traditional patterns of stressed and unstressed syllables. For instance, an unstressed syllable followed by a stressed syllable is a type of foot called iambic. A poet who repeats five iambic feet per line is said to be writing in the meter of iambic pentameter. As you can see, there's no single right way to measure lines and set line breaks. In fact, many poets writing today, don't use any of these counting methods.
Instead, they write free verse, a type of poetry that allows them to break lines wherever they choose. Along with the freedom, however, comes responsibility. Poets who write free verse need to consider each line carefully, both as an individual unit of composition and as part of a larger whole. Is the line longer or shorter than those around it? Does the line begin and end well? Does it come to an end stop with a period, or is it enjambed with the next line? And what about sentence rhythms, syntax--phrases and clauses? How are they affected by the line breaks? Yes, even free verse can get quite complex.
But don't let that stop
you. Invent. Experiment. Notice
how patterns of sound
and image can
cluster and splinter, depending
on your decisions.