The Arrow and the Song by Henry Wadsworth Longfellow is made up of three stanzas, each four lines' long. Each line is either eight or nine syllables long and rhymes with the last so that there is a total of eight couplets.

Parallelism is important in the poem. The first and second stanza strongly mirror each other grammatically— and, in fact, share an identical line. In each of the first two stanzas, the narrator takes an action, and then states he could not know the consequences of this action. He then explains why he could not. The final stanza reestablishes this parallelism of the previous two stanza within a single stanza. The first two lines of the final stanza conclude the actions begun in the first stanza, while the second two lines conclude the actions begun in the second stanza.

In this poem, the arrow represents careless and angry words thrown out, that while surely infertile, yielding no fruit, are capable of sticking in someone's crawl for a long time. They are not forgotten, but they are also perhaps sterile. On the other hand, words of kindness and joy, as represented via the song, are just the opposite. They can spread to everyone, just like planting a seed. In this sense, the poem is simply a short moral tale urging us to share joyful words, as opposed to getting angry and shouting at someone.