How is Portia's mood similar to and different from Antonio's in the first act of The Merchant of Venice?
In the first scene which features Antonio, the merchant is melancholy and depressed, but no one knows why. Antonio admits only that his depression is not the result of love or business problems.
Similarly, when the audience first meets Portia, she is talking to her maid Nerissa and discussing her desire to honor her deceased father's wishes (in carrying out the casket plot) and her desire to choose whom she wants to marry. She is conflicted just as Antonio is, but the audience knows the source of Portia's internal struggle.
The two characters do differ, though, early on in the play. Antonio seems to be too rash in trusting others and in entering into risky business dealings. In contrast, Portia is savvy and has the innate ability to "read" people. She is also a much more optimistic person.