Iambic pentameter is a meter in poetry, consisting of lines with five feet (hence "pentameter") in which the iamb is the dominant foot (hence "Iambic"). Iambic rhythms are quite easy to write in English and iambic pentameter is among the most common metrical forms in English poetry. Like the rest of the meters it has its origins in Greek poetry.

William Shakespeare, like many of his contemporaries, wrote poetry and drama in iambic pentameter. Here is an example of iambic pentameter from Christopher Marlowe's "Dr Faustus":

Was this the face that launch'd a thousand ships

And burnt the topless towers of Ilium?

When read aloud, such verse naturally follows a beat. There is some debate over whether works such as Shakespeare's and Marlowe's were originally performed with the rhythm prominent, or whether it was disguised by the patterns of normal speech as is common today. In written form, the rhythm looks like this:

da-DUM da-DUM da-DUM da-DUM da-DUM

(weak STRONG / weak STRONG / weak STRONG / weak STRONG / weak STRONG)

Was-THIS the-FACE that-LAUNCH'D a-THOU sand-SHIPS

Although strictly speaking, iambic pentameter refers to five iambs in a row (as above), in practice, most poets vary their iambic pentameter a great deal, while maintaining the iamb as the most common foot. The second foot of a line of iambic pentameter is almost never altered. The first foot, on the other hand, is the most likely to be changed, often in order to highlight a particular word or mark a shift in a poem. A trochaic inversion, in which a trochee is substituted for an iamb in the first foot, is perhaps the most common alteration of the iambic pentameter pattern.

Here is the first quatrain of a sonnet by John Donne that demonstrates how poets use variations in their iambic pentameter:

Batter my heart three-personed God, for you

as yet but knock, breathe, shine and seek to mend.

That I may rise and stand o'erthrow me and bend

Your force to break, blow, burn and make me new.

The rhythm is:

DUM da  | da  DUM | da  DUM | da  DUM | da  DUM
da  DUM | da  DUM | DUM DUM | da  DUM | da  DUM
da  DUM | da  DUM | da  DUM | DUM DUM |dada DUM
da  DUM | da  DUM | DUM DUM | da  DUM | da  DUM

Donne uses a trochaic inversion in the first line to stress the key verb, "batter", and then sets up a clear iambic pattern with the rest of the line (da DUM da DUM da DUM da DUM). He uses spondees in the third foot to slow down the rhythm when he lists verbs in lines 2 and 4. The parallel rhythm and grammar of these lines highlights the comparison Donne sets up between what God does to him "as yet" (knock, breathe, shine and seek to mend"), and what he asks God to do ("break, blow, burn and make me new"). Donne also uses enjambement between lines 3 and 4 to speed up the flow as he builds to his desire to be made new. To further the quickening effect of the enjambement, Donne puts an anapest (dada DUM) in the final foot, carrying you to the next line.

Most poets who have a great facility for iambic pentameter frequently vary the rhythm of their poetry as Donne does here, both to create a more interesting overall rhythm and to highlight important thematic elements. In fact, the skilful variation of iambic pentameter, rather than the consistent use of it, may well be what distinguishes the rhythmic artistry of poets like Donne, Shakespeare, Milton, and the 20th century sonneteer Edna St. Vincent Millay.

See also

• Blank verse
• Heroic couplet
• iamb
• sonnet
• Meter (poetry)