Alliteration occurs with what words in "Fire and Ice" by Robert Frost?

Robert Frost's "Fire and Ice" weaves together ongoing alliteration of /s/ and /f/ sounds ("Some say," "ice," "tasted," "twice," "say," "destruction," "also," and "suffice"; "fire," "From," "favor," "enough of," "for," "suffice"). These are smooth, slippery consonant sounds. In linguistics, they are classified as fricatives. This means a speaker allows air to flow through the mouth to produce them, instead of stopping the air in some way; the speaker must also constrict the opening of the mouth somewhat to control the quality of the sound produced. Creating this kind of sound is a literal embodiment of the flowing, elemental forces that Frost's poem invokes.

Likewise, Frost intersperses more staccato consonants to develop the poem's message, alliterating with /t/ and /d/ ("what," "tasted," "twice," "hate," "to ... that ... destruction," "great"; "world," "desire," "hold," "destruction") creating some sonic punctuation at critical points in the rhythm and content of the poem. These are sounds that linguists call stops, because the mouth has to stop the flow of air to make them. The placement of the word "great" serves as a humorous punchline after the turning point of the poem; the /g/ sound is an even stronger form of linguistic "stop," called a glottal stop, and deviates from the more literary and lyrical tone of the rest of the poem.

This alternation between sounds and degrees of formalness signals to the reader to interpret the poem on multiple levels of meaning. There are allegorical undertones in the first half of the poem, invoking a vaguely philosophical question of how "the world will end," and perhaps provoking the reader to think about human nature or the natural order of things. But there is also a deeply personal, psychological level that Frost brings into play in the second half of the poem; you can imagine him recalling specific episodes in his own life of feeling or witnessing the bite of coldness coming from another person's hatred. These different kinds of "ends," the burning of fire and freezing over by ice, come across in alliteration through a flow of fricatives, punctuated by a handful of sharp stops.