1. In lines 2 and 3 of “Sonnet 73,” the speaker mentions that his lover will notice his “yellow leaves, or none, or few” that “shake against the cold.” Based on these lines, the reader can infer that the time of year alluded to in the opening line is late autumn or winter. Yellow leaves would only be possible during the fall season, while bare branches are seen in winter. This metaphor is appropriate to describe the speaker because he is presumably old and nearing death, which he addresses in the final couplet of the sonnet when he says that his lover must “leave ere long.” Because winter is a time in which nature experiences a kind of death, or hibernation, it is often used throughout literature as a metaphor for old age. 2. Instead of comparing his life to a year, the speaker is comparing his life to a single day. Twilight is the time before the sun completely sets; it is the latter part of the evening. Night, of course, is the end of each day. Like autumn and winter, the twilight and night represent old age and death. The speaker thinks that death, like the night does to the day, “seals up all the rest” of his life. 3. Another metaphor the speaker uses comes in lines 9 and 10 when he says that his lover “see’st the glowing of such fire / That on the ashes of his youth do lie.” The poet chose to make this comparison because fire provides heat and energy. One might say that the speaker compares the passion of his younger days with a fire that has consumed his physical beauty in his old age. 4. The only other simile present in the poem comes in lines 11 and 12. The speaker provides another description of his lost youth, saying that it is gone “as on the death-bed” and “consum’d with that which it was nourish’d by.” The speaker uses this simile to emphasize his comparison between his passion and youth. He uses this simile to suggest that what made him into such a passionate lover is his lust for life. This desire, though, expends so much energy that it has brought him closer to his impending death.