"Scansion," or determining the meter of a poem, is very simple: determine which syllables in each line are likely to be accented, and you have determined the basic structure of the meter. You can do this by reading aloud, overemphasizing the naturally accented syllables: mark each accent with a downward slash or accent mark: ´. Mark the non-accented syllables thus:. The number of beats (or accented syllables) per line determines the kind of meter; most nursery rhymes, for example, will be in tetrameter (four beats per line) or trimeter (three beats per line), or may alternate these two patterns. The other most common patterns are pentameter (five beats per line; especially common in English verse); hexameter (six beats per line); and, though it's rarer, dimeter (two beats per line). So, for example, to scan the following verse, you would first mark the stressed syllables as follows:
' - - ' - - ' Hickory, dickory, dock, - ' - ' - ' The mice ran up the clock. - ' - ' The clock struck one, - ' - ' The mice ran down. ' - - ' - - ' Hickory, dickory , dock.
As these markings will tell you, the verse alternates trimeter lines with dimeter: 2 trimeter, 2 dimeter, then one trimeter again. Rhyme is also an important element of scansion, and of poetry in general. To determine a rhyme scheme, mark the last stressed syllable in each line (and the unstressed syllables that follow it, if any). Conventionally, the first sound is marked as "A," the second as "B," and so on. Often poems rely on partial or half rhymes, as in "one" and "down" above: the final consonants are the same, and the vowel sounds are closely related, so they can be considered a rhyme. The pattern, then, for the verse above, would be: AABBA. Note that the rhyme pattern follows the metricalpattern: the trimeter lines rhyme on the A word; the dimeter lines on the B word. Generally speaking in adult poetry we look for places where meter breaks down, where an expectation is subverted. In nursery rhymes and nonsense verse often the pleasure derives precisely from the predictability of the verse: without even knowing the meaning of the words, we can often predict what sound will come next. Breaks in metrical pattern are sometimes used to comic effect in children's poetry; when a rhythm is established, breaking it--especially in order to insert a humorous word or concept--is often funny. Form and content, then, need to be considered together in order to determine the effect of meter and rhyme: meter by itself means nothing.