e gives his harness bells a shake To ask if there is some mistake.
This sonnet has a very rigid structure- it has a consistent iambic meter and each line is exactly 8 syllables. The rhyme scheme is consistent as well, but it is interesting- the AABA BBCB… scheme gives it an asymmetrical feel that, within the rigid structure, builds and releases tension within each stanza; just when you think the B rhyme will never come, it arrives. This feeling of tension and release is present throughout the poem- there is an eerie atmosphere in the dark forest, and the anxiety of the horse builds suspense for the reader. However, this anxiety is quelled by the anaphoric couplet which maintains the D rhyme throughout the final stanza as to refrain from building anymore tension. It also has a soothing quality to it - miles to go before I sleep- the narrator implies that, though it is long, he is prepared for his journey, he is not lost, and knows just how long he has to go.