Poetry analysis is the process of investigating a poem's form, content, structural semiotics and history in an informed way, with the aim of heightening one's own and others' understanding and appreciation of the work.
The words poem and poetry derive from the Greek poiēma (to make) and poieo (to create). One might think of a poem as, in the words of William Carlos Williams, a "machine made of words". A reader analyzing a poem is akin to a mechanic taking apart a machine in order to figure out how it works.
There are many different reasons to analyze poetry. A teacher might analyze a poem in order to gain a more conscious understanding of how the poem achieves its effects, in order to communicate this to his or her students. A writer learning the craft of poetry might use the tools of poetry analysis to expand and strengthen his or her own mastery. A reader might use the tools and techniques of poetry analysis in order to discern all that the work has to offer, and thereby gain a fuller, more rewarding appreciation of the poem. Finally, the full context of the poem might be analysed in order to shed further light on the text, looking at such aspects as the author's biography and declared intentions, as well as the historical and geographical contexts of the text (though Formalism would deny any significant analytical value for context).
Overview
"The Destruction of Sennacherib", by Lord Byron
One can derive pleasure from two of the most fundamental tools in the poet's toolbox—meter and rhyme—without necessarily knowing a lot of terminology. Consider, for example, the first stanza of Byron's "The Destruction of Sennacherib":
The Assyrian came down like the wolf on the fold, And his cohorts were gleaming in purple and gold; And the sheen of their spears was like stars on the sea, When the blue wave rolls nightly on deep Galilee.
Byron's use of meter and rhyme is especially evident and rewarding when one reads the lines out loud. The lines have a powerful, rolling, and very evident rhythm, and they rhyme in a way that is impossible to ignore. In other words, the physicality of the language—how it sounds and feels—accounts for a large measure of the poem's effect. The poem does not have a deep, hidden, symbolic meaning. Rather, it is simply pleasurable to read, say, and hear.
Critical terminology becomes useful when one attempts to account for why the language is pleasurable, and how Byron achieved this effect. The lines are not simply rhythmic: the rhythm is regular within a line, and is the same for each line. A poem having a regular rhythm (not all poems do) is said to follow a certain meter. In "The Destruction of Sennacherib", each line has the basic pattern of two unstressed syllables followed by a third stressed syllable, with this basic pattern being repeated four times in a line. Those basic patterns are called feet, and this particular pattern (weak weak STRONG) is called an anapest. A line with four feet is said to be in tetrameter (tetra-, from the Greek for four). This poem has a pleasurable and appropriate rhythm, and that rhythm has a name: this poem is written in anapestic tetrameter. (This process of analyzing a poem's rhythms is called scansion.) The poem also rhymes (not all poems do), and the rhymes follow a pattern (they do not have to). In this case, the rhymes come right next to each other, which emphasizes them, and therefore emphasizes the sound, the physical nature, of the language. The effect of the poem's language derives in part from Byron's choice of an appropriate pattern of rhyme (or rhyme scheme): these adjacent, rhyming lines are called couplets. The sound, the physical nature, of the language is also emphasized by alliteration, as in the repetition of s sounds in the third line: "And the sheen of their spears was like stars on the sea".
Tools
Poetic forms
Poems can have many forms. Some forms are strictly defined, with required line counts and rhyming patterns, such as the sonnet (mostly made of a 14 line poem with a defined rhyme scheme) or limerick (usually a 5 line free rhyme poem with AABBA rhyme shceme). Such poems exhibit closed form. Others (which exhibit open form) have less structure or, indeed, almost no apparent structure at all. This appearance, though, is deceptive: successful open form poems are informed throughout by organic structure which may resist formal description but is nonetheless a crucial element of the poem's effect on the reading mind.