Moscow (Symbol)
The dream of moving to Moscow holds a lot of power over the characters in Three Sisters. Disillusioned with country life, the Prozorov sisters dream of returning to the urban lifestyle in which they were raised and educated. Moscow stands in as a symbol for all of their dreams and hopes, the promise of a fulfilling and satisfying life. Whenever a character invokes the dream of going back to Moscow, they are invoking the possibility of being happier, feeling more connected and purposeful. When they ultimately realize that they cannot go back to Moscow, this symbolizes the characters' acceptance of their fates, and their resignation about their own disappointment.
Trees (Symbol)
The trees become symbols in the final conversation between Irina and Tusenbach. Right before he goes off to duel Solyony, Tusenbach notices a tree and says, "Look, that tree may have withered, but it still sways in the wind with the others. That's how I think I'll be if I die: still part of life in one way or another." In this way he personifies the tree and makes it a symbol of his future dead self. Later in the play, Natasha wants to have the trees chopped down, and Tusenbach's words echo in the ears of the audience member; one cannot but think of the trees as somehow representing Tusenbach and his tragic plight.
Moscow, Moscow, Moscow (Motif)
In addition to being a symbol for a better and more hopeful life, Moscow is a word that gets repeated by Irina at various points in the play. At the end of the 2nd act, as she sits in the drawing room alone at night, Irina says to herself, "To Moscow, Moscow, Moscow." The word almost becomes a kind of meditation, a reminder that there is always something to look forward to, to hope for, even when life is bleak.
The Clock (Symbol)
In the third act, Chebutykin drunkenly drops a clock that belonged to the Prozorovs' mother, a woman whom the doctor loved. In this moment, the broken clock represents Chebutykin's carelessness, the ways that he is losing control and becoming more destructive as he ages. It also represents the ways that the past, and the remnants of the past, are slipping away from the members of the Prozorov household. Additionally, it symbolizes his lost love for the Prozorov mother, the fact that he could never be with her.
Lost Piano Key (Symbol)
In their final conversation, Irina tells Tusenbach that she cannot love him, comparing her heart to a locked piano whose key is missing. This symbolizes how special and rarefied Irina feels, out of step with the people around her. It also symbolizes the fact that Tusenbach, no matter how hard he tries, will never be able to win her love.