Reference: Punctuation in Poetry
In response to many recent questions about punctuation in poetry, whether there should be commas or pauses at the ends of lines, etc., I offer this reference. Of course, unless you're following a particular form, there are no rules. However, these terms may help you.
While some modern poetry has no punctuation at all, most poetry is punctuated the same as a running sentence. If you choose to use sentence punctuation, using sentence case (capitalizing starts of sentences rather than the start of every line) will make things easier on readers.
When it comes to reading poetry aloud, there is some debate. Some people say to put a light pause at the end of every line regardless of punctuation. Others say line breaks are a visual element of the poem, so when you read poetry aloud you should follow the punctuation. Since both line breaks and punctuation contribute to the meaning of a poem, it's probably best to read with both in mind. Reading a poem is an individual experience; try different ways and see what works best for you and the poem you're reading.
End-stopping is when there is punctuation—of any kind—at the end of a line. This is accompanied by a strong pause. The occasional end-stopped line can have a final or formal feeling. Many in a row can be used to get a jerky cadence.
Enjambment is when the line does not end in punctuation and so runs on to the next line. The end of one line should be interesting enough to catch the eye and compel the reader on, so it's best to break on words that are filled with content rather than functional words like "of", "the", or "for". In Shakespeare's Sonnet 129, enjambment causes the eye to linger on the words "shame" and "lust" , while still hurrying the reader through the breakneck pace of the poem:
The expense of spirit in a waste of shame
Is lust in action; and till action, lust
Caesura (say-ZHUR-ra, where zh is the s in "pleasure") is when there is some kind of pause, usually indicated by punctuation, in the middle of the line. When scanning a line, we can mark caesura with this symbol: || .
Alexander Pope used caesurae (the plural form of the word) to keep his heroic couplets from being dull. Notice how the pauses appear unpredictably ("Eloisa to Abelard", 1717):
Dear fatal name! || rest ever unreveal'd,
Nor pass these lips || in holy silence seal'd.
Hide it, || my heart, || within that close disguise,
Where mix'd with God's, || his lov'd idea lies...
John Donne, who packs as much into his lines as humanly possible, demonstrates all three techniques in “Holy Sonnet 14”:
Batter my heart, three-person'd God; for you
As yet but knock; breathe, shine, and seek to mend;
That I may rise, and stand, o'erthrow me, and bend
Your force, to break, blow, burn, and make me new.
What it means for you
As you look over your old poems, you may find good examples of these concepts. Or perhaps you'll want to correct something! When you write future poems, you can be more aware of how you place your punctuation.
Ultimately, there is no right or wrong way to punctuate a poem, but there are better and worse ways, depending on what you're trying to express. Understanding the three techniques and their effects will help you choose how to employ them, or not employ them. Happy writing!