Who is Gratiano? What was his role in the play Merchant of Venice?

Gratiano talks a great deal but says very little. According to Bassanio, "Gratiano speaks an infinite deal of nothing, more than any man in Venice" (I.i.l 14-15), and "His reasons are as two grains of wheat hid in two bushels of chaff' (I.i.115-16). He pleads with Bassanio to allow him to go with him to Belmont, and Bassanio consents after cautioning Gratiano to keep quiet once there, lest his enthusiasm and loose tongue reveal Bassanio's real social station and financial circumstances. Gratiano mimics Bassanio. When the latter marries Portia, Gratiano marries Nerissa. Similarly, when Bassanio gives his wedding ring to the young doctor, Gratiano is easily persuaded to do the same.

At Antonio's trial in the Court of Justice, Gratiano is extremely vocal in his criticism of Shylock. He says that Shylock's wolf-like behavior might make Gratiano believe in Pythagoras's phi losophy of reincarnation. When the tables are turned on Shylock, and Portia inquires what mercy Anton io might extend to the moneylender, Gratiano chimes in with "A halter gratis" (IV.i.379).That is, he will give Shylock a noose to hang himself, perhaps alluding to the halter Judas Iscariot used to hang himself after betraying Christ. But we must question how important and how representative Gratiano's statements are in this instance, when even his friends characterize him as something like an empty-headed loudmouth.