Analysis of stanzas 3 and 4

The third stanza represents the turning point where the poet switches from general and universal consideration to more personal ones. You can notice it from the personal pronoun “ my “ . 

This quatrain presents the youth with a few more of the speaking voice’s thoughts. He tells also about how unstable the whole world is and this leads him to consider that the youth is a nature gift, like it is told in the previous stanzas. In his mind, the speaking voice can see “time” debating with “decay” over how to “change your day of youth to sullied night”. This means that the fair youth is becoming old and it is a force that can’t be stopped. Indeed “ sullied night” stand for “ decay and old “. Shakespeare personifies “time” and “decay” by giving them the ability to made decisions as if they are human beings.

In the last lines of the sonnet , the rhyming couplet, the speaking voice tells to the fair youth that he is in a constant battle with time. The poet fights against time and he gives to the fair youth new life through his poem. In this way the fair youth might gain immortality and be eternity thanks to the verse.

The theme therefore is the contrast between time and eternity, immortality.