Nerissa is Portia’s lady-in-waiting and confidante, and she is fiercely loyal and devoted to her. For instance, she refuses to marry Gratiano unless Portia, herself, is happily married to Bassanio, and she accompanies Portia on her trip to Venice disguised as her law clerk. 

Nerissa is an essential character for two key reasons. To begin with, Nerissa acts as Portia’s sounding board for most of the play, listening to her many concerns and offering advice when she is able, and these conversations offer the audience insight into the heroine’s thoughts and feelings. The Merchant of Venice is a predominantly masculine play. It has a disproportionately male cast and many significant scenes take place within traditionally masculine spaces such as places of business and city streets. However, Nerissa and Portia’s relationship carves out a feminine sphere where Portia can speak her mind to a kindred spirit without the threat of masculine interference.

Her relationship with Gratiano also parallels Porta’s relationship with Bassanio. Clearly, Portia and Bassanio are the main love story in The Merchant of Venice. Their relationship appears transactional—Bassanio hopes to erase his debts by marrying a wealthy heiress. Comparatively, Nerissa and Gratiano’s abrupt marriage seems to be based on affection. For instance, Gratiano tells Bassanio “You saw the mistress, I beheld the maid” (3.2.198), and the juxtaposition of the words “mistress” and “maid” illustrates Gratiano’s wish to marry Nerissa because he fell in love, not because of her economic prospects. Further, Bassanio “saw” Portia; Gratiano “beheld” Nerissa, and his more poetic word choice suggests he sees his own courtship as more romantic. However, it’s worth mentioning that the couple’s choice to marry only if Portia and Bassanio were to do so strengthens the legitimacy of Nerissa’s love for Portia while potentially weakening the legitimacy of her feelings for Bassanio. That their marriage is dependent on another’s renders their love somewhat reactionary, and while Gratiano may characterize his feelings as genuine and passionate, he is no less willing than Bassanio to hypothetically sacrifice the life of his new wife if it might save Antonio during the trial.