Iambic Pentameter

  The term iambic pentameter describes a line made up of five groups of syllables, or "feet", each of which is made up of an unstressed syllable followed by a stressed syllable. It is used in many major poetic forms, including sonnets and plays, such as the Merchant of Venice by William Shakespeare.
  Iambic pentameter will make the lines in the play sound smoother and more elegant without risk making it sound artificial. A speech delivered in it sometimes will end in a rhyming couplet to add an emphasis or a dramatic finish to it, such as in Act One, Scene Three, when Antonio says to Bassanio, "Come on: in this there can be no dismay; My ships come home a month before the day."
  Shakespeare also makes extensive use of blank verses, which is poetry written in unrhymed iambic pentameter. He uses blank verse for irregular speech, such as  in this exchange from King John, where one blank verse line is broken between two characters:
My lord?

A grave.

He shall not live.

Enough.