Here's why:
* Blank verse is unrhymed iambic pentameter, meaning it has 5 metrical feet per line, each consisting of an unstressed syllable followed by a stressed syllable.
* This form gives a natural flow and rhythm to the dialogue, allowing for the characters' emotions and thoughts to be expressed with a sense of realism.
* Shakespeare often uses blank verse for the main characters in his plays, creating a more formal and elevated style.
While the language is poetic, it's not as overtly poetic as some of the other forms Shakespeare uses (like sonnets). The conversational nature of their first encounter is well-suited to the natural flow of blank verse.