"The Brook" by Alfred, Lord Tennyson reveals various literary devices including alliteration, all of which contribute to its purpose. The poem expresses the benefits of perseverance and offers its own enduring qualities as proof that "I go on forever." Change can be a good thing and the poem offers a playful glimpse of the view from the brook's perspective: never taking things too seriously but enjoying the journey to the "brimming river."
Alliteration is a sound device which relies on the repetition of the first letter or sound of a word to provide a certain emphasis within a poem. In this case, the third stanza uses alliteration when it speaks of the brook and the direction it is taking. The brook describes its journey and how "by Philip's farm I flow." The repeated "f" sound- including the phonetic sound of "ph"- contributes to the poem as it describes the direction that it goes, which the reader can interpret literally - because it really is a brook and the visual image created by the alliteration is one of water in an unbroken current - or can interpret symbolically, appreciating it from the reader's own perspective and placing the reader at the point where the river actually flows past Philip's farm. Although personification is used because the brook is the narrator, the reader is satisfied that the brook still has its own unique qualities and does the things a person would expect of a brook by revealing its "flow." The alliteration ensures this and does not disappoint the reader.