“Leave” echos “leaves” in the first lines and draws the reader’s mind back to the first quatrain. Though the speaker does not overtly say that he is the “love” that the youth must leave, the two words create the impression of, or memory of, the speaker in these final lines. In other words, rather than explicitly state that he is the object that the youth must love and lose, the speaker inserts the ghost of himself into the couplet by repeating a word from the beginning of the poem. In addition, the vast separation between “leaves” and “leave” mimics the eventual separation that will cleave the speaker from his beloved.
“That” is yet another deictic pronoun. On a literal level, “that” is the wood which feeds the fire and eventually becomes the ash that suffocates the flame. However, on a metaphorical level, “that” signifies “time,” which both gives and takes away life. “That” could also refer to the speaker’s love of the youth, which is both all-consuming and destructive to his creative impulse and the fuel that nourishes his poetic fire.
As the second quatrain opens, the speaker shifts to a new temporal metaphor. The initial conceit of a human life as a year gives way to a conceit of a life as a day. The autumn of the year finds its parallel in the day’s twilight. The use of “such” suggests a stacking of these temporal metaphors: the speaker’s stage of life is like the twilight of an autumn day.
“Bare ruined choirs” can refer to the aforementioned “boughs,” which serve as the location for a “choir” of “sweet birds.” The bareness of the boughs marks a subtle seasonal shift from autumn—when “yellow leaves… do hang”—to winter, when the leaves are gone.
“Those” is yet another deictic moment in this poem that causes the reader to question which boughs? The deixis within this poem could come from the speaker’s inability to know the youth’s thoughts: if this is his assumption of what the youth sees within him, then he is describing the idea of an idea rather than something concrete.
The speaker uses himself as a frame for all of the imagery he produces in the sonnet’s three quatrains. The autumn scene, the setting sun, and the smoldering fire are all “in me.” He underscores this frame by beginning the second and third quatrains identically, with the phrase “In me thou seest.” This is an imaginative move: the fair youth cannot truly see the speaker’s vivid metaphors.
In saying that the youth “mayst” behold the following images, the speaker makes the first quatrains of this poem hypothetical. Rather than claiming that he has knowledge of the youth’s thoughts, he reveals that these ideas are merely an assumption of how the youth views the speaker.
In starting this poem with the pronoun “that,” the speaker places this sonnet in an ambiguous space that causes the reader to ask what time of year? This ambiguity is a poetic device called deixis, in which a writer intentionally leaves a pronoun’s referent unclear in order to suggest multiple referents or cause the reader to impose their own meaning onto the pronoun.
