Usually, Shakespeare gives his plays a healthy dose of verse (mostly iambic pentameter). But, The Merry Wives of Windsor is different because it has more prose than any other Shakespeare play. (Prose, by the way, is how ordinary people like us talk every day—it's just regular old speech that doesn't have any metrical pattern or rhyme scheme.) That makes a lot of sense given that the play is set in a rural town full of a lot of middle-class folks. In his other plays, the nobility tend to speak in verse while the everyday Joes speak prose.
But, just because the play is mostly prose doesn't mean it's boring. Shakespeare is the king of snappy banter and clever word play so his dialogue is loaded with puns and innuendo. We talk more about this in "Themes: Language and Communication" and also in "Character Clues: Language and Dialogue." See you there.