Shakespeare wrote both in prose—unrhyming, unmetered lines—and verse. A Midsummer Night’s Dream, specifically, features trochaic verse in addition to iambic pentameter. 

Characters in Shakespeare’s works often speak in prose to denote a lower status or a more familiar relationship. In Dream, the mechanicals often speak in prose; for example, in Act I, Scene 2, Bottom replies to Quince, assigning parts for their play: 

BOTTOM. Let me play the lion too. I will roar that I will do any man’s heart good to hear me. I will roar that I will make the Duke say “Let him roar again. Let him roar again!” (1.2.68-71). 

Characters in Shakespeare’s works often speak in verse to denote that they are noble or of the upper-class. Shakespeare uses blank-verse, in which there is no rhyme, but an internal rhythm; he mostly favors iambic pentameter. An iamb is a metrical foot consisting of one unstressed syllable and one stressed syllable; pentameter indicates that each line has five of these metrical feet. (Iambic verse is often compared to the human heart beat, a steady da-DUM, da-DUM.) The lovers in Dream often use verse in their language; the following shows unstressed syllables as not bolded and stressed syllables as bolded:  

LYSANDER. How now, my love? Why is your cheek so pale?

How chance the roses there do fade so fast?

HERMIA. Belike for want of rain, which I could well 

Beteem them from the tempest of my eyes. (1.1.130-133)

Characters in Dream also speak in trochaic verse from time to time; Shakespeare uses it when the fairies were engaging in magic and chanting spells. Trochaic verse is the inverse of iambic verse, with each metrical foot consisting of a stressed, then unstressed syllable. The verse, shortened by one syllable often, is used to distinguish the words spoken from the majority of the words spoken:

OBERON. Flower of this purple dye,

Hit with Cupid’s archery,

Sink in apple of his eye (3.2.104–106).