Two key literary techniques used in the poem “Tree at My Window” by Robert Frost are personification and metaphor. As literary devices, they transcend the text of poem from actions described literally to figurative meanings that are open to interpretation.
In personification, an inanimate object or inhuman being is given human characteristics or “personified” as human. Personification is a fairly common literary device in poetry and other forms of literature. It is recognizable especially when non-humans do human things, such as talking using human language or performing human tasks. For example, in the poem, Frost refers to the tree as having “seen” him, as if the tree has eyes like a person. He also refers to the tree with the personal pronoun “you” rather than “it,” which reinforces the idea of a tree with human qualities.
Further, referring to as if the tree has eyes and as if it is a person works as an extended metaphor throughout the poem. Throughout the poem Frost describes concrete and literal actions that speak to an ongoing relationship with the tree. He refers at the beginning of the poem to going to sleep at night and, subsequently, to dreaming. He refers once again to the tree as having “seen” him in dreams. This second reference works metaphorically by hinting at a metaphysical or spiritual relationship with the tree in particular and with nature-at-large. Frost reinforces the metaphysical/spiritual by ending the poem in reference to an inner life, possibly a soul.