That desire might be the darker side of marriage is the play’s overarching thematic example of the structure of duality that shapes A Midsummer Night’s Dream. Those doubled lovers are part of a system of doubling and double-vision that extends throughout the play. For a start, A Midsummer Night’s Dream makes heavy use of rhymed couplets: more than half of its lines are rhymed, and this high proportion is amplified by companion rhetorical devices that repeat phrases and syntax to create linguistic echoes.