Iambic Pentameter Checker

What iambic pentameter is

A foot is one unit of rhythm in a line of verse. An iamb is a two-syllable foot with the weight on the second syllable: da-DUM, like the words "away," "today" or "compare." Pentameter means five feet per line. Put them together and you get ten syllables that alternate unstressed and stressed, five times.

It is the most common meter in English poetry because it sits close to the natural rhythm of spoken English. Shakespeare wrote most of his plays and all of his sonnets in it, Milton used it for Paradise Lost, and it is the default line of the sonnet.

How stress works (the da-DUM)

Stress is the syllable you say a little louder and longer. In words of more than one syllable it is fixed by the dictionary: it is com-PARE, not COM-pare, and WIN-dow, not win-DOW. In one-syllable words it depends on meaning. Nouns, verbs, adjectives and adverbs usually take the beat. Articles, prepositions and pronouns ("the," "a," "of," "to," "it") usually fall between beats.

To scan a line yourself, say it out loud at normal speed. Then tap the table on each syllable that feels heavier. If the taps land on syllables 2, 4, 6, 8 and 10, the line is regular iambic pentameter.

Four famous lines, scanned

Capitals mark the stressed syllable. The bar marks a foot break.

• “When I do count the clock that tells the time” (Shakespeare, Sonnet 12)

  when I | do COUNT | the CLOCK | that TELLS | the TIME

  Five clean iambs and ten one-syllable words. The stress comes from meaning: the nouns and verbs carry it, the small words fall between.

• “But soft, what light through yonder window breaks?” (Shakespeare, Romeo and Juliet)

  but SOFT | what LIGHT | through YON | der WIN | dow BREAKS

  Regular, and a good example of feet crossing word boundaries: "yonder" and "window" each split across two feet.

• “Now is the winter of our discontent” (Shakespeare, Richard III)

  NOW is | the WIN | ter OF | our DIS | con TENT

  Opens with a trochee (DUM-da) instead of an iamb, the most common variation in English verse. Foot three puts its beat on "of", a light word that takes the stress only because of where it sits in the line.

• “To be, or not to be: that is the question” (Shakespeare, Hamlet)

  to BE | or NOT | to BE | that IS | the QUES | tion

  Eleven syllables. The extra unstressed "-tion" at the end is a feminine ending, and the line still counts as pentameter.

Common variations that still count

Almost no real poem, including Shakespeare's own sonnets, is perfectly regular line after line. Poets vary the pattern to stress a word or break the sing-song effect. These are the variations you will see most often:

• Trochaic inversion. The first foot flips to DUM-da, as in "NOW is the winter." It is so common at the start of a line that most readers don't notice it. It also appears after a mid-line pause.
• Feminine ending. An extra unstressed syllable at the end makes 11 syllables, as in "that is the QUES-tion." This is frequent in the plays.
• Headless line. The opening unstressed syllable is dropped, so the line starts on a beat and has 9 syllables.
• Spondee and pyrrhic. Two stressed syllables in a row (DUM-DUM), or two light ones (da-da), in place of an iamb. They often come in pairs that balance out.

How this checker decides

1. It counts the syllables in your line. Pentameter in the strict form needs exactly 10.
2. It looks up each word's stress in the CMU Pronouncing Dictionary, the same data the rest of this site uses, and joins them into one da/DUM pattern for the line.
3. It marks the line as perfect only when the pattern is exactlyda-DUMfive times.

Limits. The dictionary gives every word one stress pattern out of context, so short words like "to," "in" or "I" can be marked stressed when a natural reading would weaken them. The strict check also flags the accepted variations above as "not perfect." Words the dictionary doesn't know show as ? rather than a guessed stress, because a wrong guess about stress would be misleading. Treat the result as a second opinion and read the line aloud.

Writing a sonnet? Check the end-rhymes with the rhyme scheme checker, count a whole draft with the syllable counter, or try a shorter form with the haiku syllable counter.