In Act 1, Scene 1, Helena is desperate because of her love for Demetrius. She uses figurative language to express the depth of her feelings when she runs into her friend Hermia. Specifically, personification helps Helena convey her envy and longing; because Demetrius loves Hermia, Helena feels helpless. After Hermia complains that he loves her even though she shows no interest in him, Helena responds with an expression of jealousy, complimenting her friend and lamenting her own shortcomings. She says:
O, that your frowns would teach my smiles such skill!
In this section, instead of saying that she wishes for Hermia to teach her how to attract Demetrius, Helena uses personification. She personifies Hermia’s frowns because she wishes that their power to produce a feeling of love in Demetrius could be transferred to her smiles. Her personification implies a certain history of her interactions with Demetrius—interactions in which she smiles and he doesn't respond with the affection she wants. This use of personification therefore gives context to the depth of Helena’s feelings for Demetrius. She asks Hermia’s frowns to be her teacher out of desperation. Characterizing Helena in this way helps deepen the relationships between the four lovers, whose resulting drama will produce, in turn, both laughter and sympathy from the audience.
Helena’s soliloquy in Act 1, Scene 1 takes place after she runs into Hermia and Lysander. They have just told her that they intend to flee Athens and live together, away from the Duke’s tyrannical rule. Over the course of the soliloquy, she uses personification to reflects on the happiness of the lovers and on her own misery. She then decides to tell Demetrius that Hermia is leaving. Her use of personification characterizes her view of love and therefore helps the audience understand the motivation behind her decision. She says:
Love looks not with the eyes but with the mind;
And therefore is winged Cupid painted blind.
Helena uses personification in these lines, giving love itself the power to look. She gives love the power of sight, and implies that love has a mind of its own. This makes love seem as though it has an inherent nature, and it shows how powerless Helena feels to change Demetrius’s mind. Helena’s philosophy of love is reflective of her situation, which has caused her a great deal of pain. Her statement here will be counteracted by events that take place later in the play, when Demetrius and Lysander will be bewitched by a love potion. Because of the magic of the fairy world, their love for Helena will come about just by looking at her. In that case, their love will actually "look with the eyes," confounding both Hermia and Helena. This early use of personification helps the audience understand why what happens in the woods makes Helena so confused and angry. It allows her to express her philosophy of love so that her later disbelief fits within what the audience already knows about her.
In Act 2, Scene 1, Oberon and Titania meet each other and argue over the custody of a small boy. Their conflict is a powerful one, and, as the rulers of the world of the forest, their turmoil is reflected in the atmosphere around them. Titania describes the effect that their conflict has had on the changing of the seasons, using personification to give the moon human attributes and therefore emphasize the extent of her power and displeasure. According to Titania, because of her conflict with Oberon, the moon has grown angry. Titania says:
No night is now with hymn or carol blessed.
Therefore the moon, the governess of floods,
Pale in her anger, washes all the air,
That rheumatic diseases do abound.
Titania calls the moon a "governess" and gives it emotions and some agency over the atmosphere. Her personification of the moon gives the impression that the natural world is responsive to the fairy realm. The moon is especially significant as a symbol because its presence is vital to the nighttime forest and precipitates a romantic atmosphere for many of the characters. Her anger is therefore a way for Titania to explain how disruptive she and Oberon’s fight has been, and how they have displaced the loving atmosphere of calm moonlight. Titania’s language is especially elemental, and her invocation of the moon, who guides the floods and washes the air, creates a greater sense that the woods are magical. Titania’s consistent references to the natural world make her seem as though she belongs to its magic. This instance of personification has this exact effect: she and Oberon become a part of the language of the forest, and their conflict’s effects are widely felt.
In Act 3, Scene 1, Titania uses personification while bewitched, as she is leading her new lover, Bottom (with his ass head), to her bed. Titania has had a magical love potion put on her eyes while she was sleeping and has therefore fallen madly in love through a trick. Her love gives her a single-mindedness that distracts her from the boy in her custody, giving Oberon an opportunity to take him away. In this scene, therefore, she is very focused on bringing Bottom back to her bower. Everything around her seems to enforce her desire. She asks her attendants to lead him there, and says:
The moon, methinks, looks with a wat’ry eye,
And when she weeps, weeps every little flower
Lamenting some enforcèd chastity.
In her speech, Titania personifies the moon by giving it the power to weep. The moon’s eyes and tears produce a response in the flowers. Titania’s use of personification gives the moon and the flowers human characteristics in order to make it seem as though they too are missing out on consummating their love. Titania’s desires are so grand that they extend to all of the beings around her, and her love gives them uncharacteristic powers. Because Titania’s love for Bottom came out as soon as she looked at him, she gives the moon and the flowers eyes. This expression of her love is made richer through her use of personification, and it also characterizes her as someone for whom the natural world has emotion and agency: the moonlight especially impacts her and the way she moves through the world.