Iambic pentameter () is a type of metric line used in traditional English poetry and verse drama. The term describes the rhythm, or meter, established by the words in that line; rhythm is measured in small groups of syllables called "feet". "Iambic" refers to the type of foot used, here the iamb, which in English indicates an unstressed syllable followed by a stressed syllable (as in a-bove). "Pentameter" indicates a line of five "feet". Iambic pentameter is the most common meter in English poetry. It was first introduced into English by Chaucer in 14th century on the basis of French and Italian models. It is used in several major English poetic forms, including blank verse, the heroic couplet, and some of the traditionally rhymed stanza forms. William Shakespeare famously used iambic pentameter in his plays and sonnets, John Milton in his Paradise Lost, and William Wordsworth in The Prelude. As lines in iambic pentameter usually contain ten syllables, it is considered a form of decasyllabic verse. Meter Example An iambic foot is an unstressed syllable followed by a stressed syllable. The rhythm can be written as: da DUM The da-DUM of a human heartbeat is a common example of this rhythm. A standard line of iambic pentameter is five iambic feet in a row: da DUM da DUM da DUM da DUM da DUM Straightforward examples of this rhythm can be heard in the opening line of William Shakespeare's Sonnet 12: When I do count the clock that tells the time and in John Keats' Ode To Autumn: To swell the gourd, and plump the hazel shells It is possible to notate this with a "/" marking ictic syllables (experienced as beats) and a "×" marking nonictic syllables (experienced as offbeats). In this notation a standard line of iambic pentameter would look like this: × / × / × / × / × / The scansion of the examples above can be notated as follows: × / × / × / × / × / When I do count the clock that tells the time × / × / × / × / × / To swell the gourd, and plump the hazel shells The iamb in classical and English verse The term "iamb" originally applied to the quantitative meter of classical poetry. The classical terms were adapted to describe the equivalent meters in English accentual-syllabic verse. Different languages express