Sonnet 73 belongs to the section of Shakespeare's sonnets adressed to a young man who was Shakespeare's patron.

In these sonnets Shakespeare explores the themes of platonic love and passing time.

Sonnet 73 displays the typical layout of the Elizabethan sonnet: three quatrains and a final rhyming couplet. The rhyme scheme is ABABCDCDEFEFGG, the speaking voice of the sonnet is the poet himself and we can detect some run-on-lines for example in lines 5-6.

In the first three quatrains the poet provides a description and a narration, while in the final couplet he draws a conclusion. At the beginning of each quatrain he compares himself to an element which belongs to the natural world: in the first one he mentions autumn, in the second one he mentions the twilight and in the last one he compares himself to a "glowing fire". These are all metaphores that convey the idea of passing time and the approach of an end. The intelligent reader understands that the poet suffers as he knows the fact he is growing old, while the person he dedicates  the poem to is young. In order to emphasise the concept of the end of life and the suffering of growing old, the poet uses images which are very significant and complex: "yellow leaves, or none, or few, do hang upon these boughs"; " bare ruined choirs"; "sunset fadeth in the west"; " black night"; "the ashes of his youth"; "deathbed". He seems not to be only sad for himself, but also for the fact that the young men's youth will fade somebody and so in the final couplet he suggests him to appreciate his present condition because it won't last forever.