Answer:
The best answer to the question: Where does the poem shift in the poem, would be, A: The tone shifts in the last two lines.
Explanation:
This excerpt comes from William Shakespeare´s Sonnet 97, and which was published around 1609. When analyzing the stanzas, you realize that in the first quatrain of the poem, the speaker is merely talking about having been forced to go through a process of separation from someone that is loved, and therefore, the tone is saddening, almost like how winter´s effects look. Then, he goes on to say that maybe it is not so saddening, like trying to look on the brighter side of things, by comparing the feelings more to autumn, or late summer.
But in the final part of the poem, the speaker goes to deny his optimism about this separation, making the poem seem really sad, even more so than at the start. Now, it is almost tangible, in the last two lines, the sadness felt for the separation. So much so, that even if there were a single joyful thing, like the song of a bird, it would still be with "so dull a cheer/ That leaves look pale, dreading the winter´s near."
