In many of Shakespeare’s works, night is metaphorically compared to death, perhaps most notably in Hamlet, in which Prince Hamlet asks “for in that sleep of death what dreams may come?”, and in Macbeth, in which Macbeth praises sleep—“the death of each day’s life”—after murdering King Duncan.

The consonance of three s sounds in "sweet," "birds," and "sang," helps to create the auditory imagery of birds chirping. The image of songbirds alludes to the joyful and poetically productive past that the speaker nostalgically laments.

“Love” here could reference multiple ideas that the poem has brought up. The lost “love” could be the speaker, who will die and leave the youth behind. It could also reference the youth’s own life and beauty. This second reading of the line makes the poem a commentary on the ephemerality of all life, not just his own. All men, even the youth, cherish their lives because their lives will inevitably end in death.

“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.

The use of “that” allows the final couplet’s sentiment to resonate on two registers. “That” refers to the speaker himself, the object well loved by the fair youth. The language is vague enough that the specific characters disappear. “That” also refers, more broadly, to all that one “must leave ere long.” In a similar way, we can read “thou” as a hypothetical you, a nod to all. Thus, the couplet offers a universal meditation: as humans, we love most those we must soon leave.

There is a notable rim rhyme between “love” and “leave,” a play of sound which underscores the necessary relationship between the two. To love requires one to eventually leave the beloved. That the rhyme falls on two of the line’s stresses deepens the echo.

This line represents the first time the speaker overtly references the nature of his relationship with the youth if the reader chooses to read “thy love” as the youth’s love for the speaker. “Thy love” suggests that the two men have a relationship, and that the youth’s love for the speaker is strengthened by “this,” whatever it may refer to.

The reader’s understanding of “this” affects their reading of “thy love.” If “this” is the speaker’s love for the youth, then “thy love” could refer to the youth’s love for the speaker: the speaker’s portrayal of his consuming love makes the youth love him more. If “this” is the speaker’s aging, then “thy love” could refer to the youth’s self-love or narcissistic love of his beauty: in watching the speaker age, the youth loves his youth even more. “Thy love” could also be a syntactically fraught way of saying my love for you, “thy” characterizes rather than possesses “love”, which would mean that the youth’s ability to perceive the speaker’s internal anguish makes the speaker’s love for him more strong.

“This” is another deictic moment. “This” could refer to the aging of the speaker that the youth has witnessed throughout the poem or it could refer to the speaker’s “consuming” love for the youth.

The imagery that the speaker creates here – fire being consumed by that which gave it birth; the death-bed and youth being inextricably linked — alludes to the idea of the phoenix. A phoenix is a mythological bird that lives for a century, self-immolates, and is then reborn from the ashes. The phoenix is a symbol for immortality and the cyclical nature of life and death. This imagery suggests that the speaker’s has an accepting attitude towards inevitable death.

This line echoes the Metamorphosis in which Ovid describes Helen of Troy aging: “The daughter of Tyndarus weeps, too, as she beholds in her mirror the wrinkles of old age, and enquires of herself why it is that she was twice ravished. Thou, Time, the consumer of all things, and thou, hateful Old Age, together destroy all things; and, by degrees ye consume each thing, decayed by the teeth of age, with a slow death” (Met, VX.234-6). This allusion recalls the previous sonnets in which the speaker railed against time as the destroyer of all things.

“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.

The use of “his” in this line is subtle. In Elizabethan parlance, “his” often served as a replacement for “its,” and granted possession to gender-neutral subjects, such as the fire. Yet the fire is a metaphor for a human life, and so the use of “his” succeeds in anthropomorphizing the fire in a fitting manner. The specifically male tone of “his” is appropriate in that the fire represents the male speaker’s dwindling life.

The speaker opens the third quatrain with a new metaphor for a human life: a fire which burns itself away. Just as the first and second quatrains related through temporal conceits, the second and third quatrains are related by light-based conceits. The word “such” often indicates a previously mentioned object, but here the speaker uses “such” to offer forth a new image.

While “rest” furthers the metaphor of sleep, it necessarily describes the oblivion of death as well. The notion that death might be “rest” offers a positive perspective on the speaker’s eventual fate. Indeed, in Sonnet 73 the speaker takes a resigned, rather than combative, stance against his primary foes—time and death.

“Seals up” carries connotations of both death and sleep. In death, a coffin “seals up” the deceased. “Seals” also suggests “to seel,” an archaic form that applies specifically to the sealing of eyes to prevent sight. Sight is an important conceit in the poem—“thou mayst in me behold”—and defines the relationship between the speaker and the fair youth. Thus the notion of being blinded in death emphasizes the eventual separation.

“Death’s second self” is a metaphor that comes full circle. The phrase is a metaphor for sleep and night, which in turn are metaphors for the underlying topic of death.

The dense consonant sounds in “Death’s second self” causes the poem’s pace to slow down. The consonant clusters, such as ths, nd, and lf are difficult to pronounce, as are the successive s sounds between the first two words. This deceleration cleverly imitates the process of aging and dying.

The syntax of this phrase confuses the meaning of these two lines. The speaker is saying that “black night” takes away the sunset and causes “all to rest.” “Death’s second self” is meant to characterize the “black night.” However, this extraneous metaphor that re-describes “black night” syntactically interrupts the idea of the phrase. It delays the time between the sunset and the “rest” that completes the day, metaphorically inserting more time into the end of the day, or the end of one’s life. The form of these lines mimics the speaker’s desire to hold on to and extend the last minutes of his fading life.

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.

“Twilight” takes its prefix from the germanic root twi, meaning “two”; thus “two lights.” This etymology is useful because the poem traces two forms of light: the setting sun in the second quatrain, and the fire which burns itself out in the third quatrain.

The image of the choir of “sweet birds” that no longer sing reinforces the idea of the speaker’s diminished poetic output . Song and poetry, after all, are classically linked. The ghost of the choir suggests a sense that the speaker’s poetry has dried up, or will.

“Bare ruined choirs” also extends the printmaking metaphor. A “choir” refers to a pair of connected leaves of paper, the central seam of which is stitched into the book’s spine. The image of “bare ruined choirs” suggests an end to the speaker’s poetic output. His pages have become “bare,” empty of verse, or “ruined” by the ravages of time.

“Bare ruined choirs” also evokes the image of abandoned churches, “choir” then metonymically referring to the area in a church where the choir sings. This serves as a historical allusion to the desecration of the Catholic monasteries during the Protestant Reformation in England. When Henry VIII left the Catholic Church in 1534, his orders left many cathedrals bare and ruined across the English landscape.

“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.

The printing press arrived in England in 1476 with printer William Caxton. It was revolutionary technology that allowed writers to reach mass audiences and preserve their work for generations. By juxtaposing print metaphors with winter, the speaker suggests that his printing endeavor has failed. “None” or “few” of his “leaves,” pages of poetry, survive against “the cold;” the “choirs,” collection of leaves in a book, are ruined. In combining images of winter with comparisons to books, the speaker reveals his worry that his poetry will not survive when it is printed; his poetry is just as subject to death as his body.

“Boughs” here means the limbs of a tree. In Early Modern England it would have evoked connotations of the gallows or the branches of a family tree. “Cold” is a reference to winter, the season that the speaker has used throughout the sequence as a metaphor for the final years of one’s life and ultimate death. In this metaphor, the speaker claims that one’s lineage, or legacy, is threatened by death. He creates a somber tone that will dominate the rest of the poem.

“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.

“Hang” furthers the dual meaning of this line. Leaves hang on trees and fall off as they die leaving “few” or “none’ there over time. However, in Early Modern papermaking, sheets of paper would be “hung” to dry after being pressed into shape. The extended printing metaphor in this quatrain makes the poem self-referential: metaphors for winter double as metaphors for the physical structures that make up the book we are reading.

“Yellow leaves” both refers to dying leaves on a tree and pages in a book. Early Modern English paper was made out of clothing scraps and generally had a yellow hue due to the papermaking process. This does not necessarily mean the paper is old, though it could also be a reference to pages in medieval books which were made on yellow vellum, animal skin paper.

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.