Having made his declaration that no man can woo Bianca until Katharina is married, Baptista and his daughters leave a frustrated and angry Gremio and Hortensio. Without the audience of Baptista and his daughters, their language becomes more coarse and idiomatic as they discuss their plight, compared to the polished and refined blank verse they spoke before. We see these two characters for the old, money-grasping men that they are as they make such comments as "Our cake's dough on both sides." As they plot to find a husband for Katharina and determine to try and win favour with Baptista by securing a tutor for Bianca, we see these men stripped of pretense and united by Baptista's restrictions. Note Gremio's last lines in particular, which are rather coarse and therefore appropriate for prose rather than blank verse:
I am agreed, and would I had given him the best horse in Padua to begin his wooing that would thoroughly woo her, wed, her, and bed her and ride the house of her! Come on.
Such sentiments and words are appropriate for the medium of prose, and also point towards the artificiality of these suitors as they try to present themselves as something they are not in blank verse.