“And”

Although it’s very common and unassuming, the most conspicuous word in Dickinson’s poem is “and.” This conjunction isn’t technically the most-repeated word in the poem—that honor goes to the definite article, “the.” However, “and” arguably serves a much more important rhetorical purpose in the poem, tied as it is to Dickinson’s use of a device known as polysyndeton (PAWL-ee-SIN-duh-tawn). This term refers to the use of multiple coordinating conjunctions in close succession. The key example of this technique appears across the divide that separates the first and second stanzas (lines 3–6):

And sings the tune without the words,
And never stops at all,

And sweetest in the gale is heard;
And sore must be the storm

The repetition of “and” here and elsewhere has a slightly hypnotic effect that conjures a sense of the hope-bird’s irrepressible nature. 

Temperature

References to temperature come up twice in Dickinson’s poem. The first reference appears in the second quatrain, where the speaker describes how hardy the bird of hope is (lines 6–8):

And sore must be the storm
That could abash the little bird
That kept so many warm.

In contrast to the “gale” mentioned in line 5, with its implied coldness, the speaker emphasizes the enduring warmth of “the little bird / That kept so many warm”—and, indeed, will continue to keep them warm. In this way, Dickinson deploys temperature in a way that links coldness to adversity (and death) and warmth to hope (and life). The speaker invokes these symbolic links again in the third quatrain, by declaring that he or she “heard [the hope-bird’s song] in the chillest land / And on the strangest sea” (lines 9–10). Here, the phrase “chillest land” may literally refer to cold places, such as the Arctic. However, this same phrase could be read figuratively, as an expression linked to places where the speaker has felt the icy “chill” of alienation or loneliness. Either way, the implied warmth of “the little bird,” mentioned earlier, is able to cut through the literal and figurative cold of “the chillest land,” restoring the speaker’s sense of hope.