Metre in poetry is the organised pattern of rhythm established through recurring units of stressed and unstressed syllables or other recurring rhythmic elements. In English poetry, metre is commonly described using metrical feet such as iambs, trochees, anapests and dactyls, combined with line lengths such as trimeter, tetrameter and pentameter. Metre creates an underlying rhythmic expectation against which actual speech can vary. It is therefore not simply the number of syllables in a line. Two lines can contain the same number of syllables while having different metres because the distribution of stresses differs.
An iamb consists broadly of an unstressed syllable followed by a stressed syllable, as in the rhythm associated with the word today when pronounced naturally. A trochee reverses this pattern, with a stressed syllable followed by an unstressed syllable. An anapest generally contains two unstressed syllables followed by a stressed syllable, while a dactyl generally contains a stressed syllable followed by two unstressed syllables. A spondee conventionally consists of two stressed syllables, although its use in English metre is often treated as a substitution rather than a continuously repeating standard foot. These feet provide analytical vocabulary for describing rhythmic patterns.
The number of feet in a line determines a common classification of metre. Monometer contains one foot, dimeter two, trimeter three, tetrameter four, pentameter five, hexameter six and heptameter seven. Iambic pentameter therefore describes a line with an underlying pattern of five iambic feet. It does not mean that every line must contain exactly ten pronounced syllables in an absolutely mechanical sequence because English poetry permits substitutions, elisions, feminine endings, extra syllables and other variations. The metrical pattern is better understood as a framework of expectation that interacts with natural linguistic stress.
Iambic pentameter is particularly important in English literature. It appears extensively in Shakespearean drama, the poetry of Geoffrey Chaucer in modified historical forms, Milton's Paradise Lost and the work of many later poets. Its widespread use reflects its capacity to combine regularity with flexibility. English speech naturally contains alternating patterns in many phrases, making iambic rhythms adaptable to ordinary syntax. Shakespeare frequently varies the expected pattern to create emphasis, characterisation or emotional disturbance. A metrical analysis should therefore consider deviations as meaningful possibilities rather than automatically treating them as errors.
Metre differs from rhythm. Rhythm is a broad concept referring to patterns of movement, stress, duration and recurrence in language, music or physical action. Metre is a more specific system of organised rhythmic expectation. A poem can have rhythm without having regular metre, as in free verse, while a metrical poem can contain rhythmic variations that depart from its underlying pattern. The distinction is especially important when analysing modern poetry because irregular rhythm does not automatically mean the absence of deliberate organisation. Metre concerns a framework, while rhythm encompasses the actual temporal and stress patterns produced in performance or reading.
Poetic traditions outside English use different metrical principles. Classical Greek and Latin quantitative metres distinguish syllables partly according to duration rather than the stress based system dominant in English. The hexameter of ancient epic therefore cannot be analysed simply using English iambic terminology. Some languages have syllable counting systems, tonal patterns or other formal principles. Historical changes in pronunciation can also affect how older English metres are perceived today. Metre must consequently be analysed within the phonological and literary conventions of the language and period in which a poem was composed.
Metrical variation is one of the principal ways poets create expressive effects. A sudden stress where an unstressed position is expected can draw attention to a word. A caesura can interrupt the rhythmic flow, while enjambment can carry syntax across a metrical line boundary. Substitution of one foot for another can alter the emotional or rhetorical character of a line. Poets may also use catalexis, in which an expected final syllable is omitted, or feminine endings, in which an additional unstressed syllable follows the final stressed position. Such variations demonstrate that metre is an expressive system rather than a rigid counting exercise.
Metre remains important because it helps explain why certain poems sound patterned, memorable and formally cohesive. It supports oral performance, establishes expectations and can interact with syntax, meaning and emotion. Readers do not always consciously identify each foot, but repeated rhythmic structures can influence how language is perceived. Understanding metre requires listening for stress as well as counting syllables and considering the relationship between the ideal pattern and its actual realisation. A strong analysis therefore identifies the underlying metrical scheme, notes significant variations and explains how those variations affect emphasis, pacing, tone or interpretation rather than merely labelling a poem with the name of a metrical form.
