How is "The Love Song of J. Alfred Prufrock" a modern poem?

T.S. Eliot's poem "The Love Song of J. Alfred Prufrock" is considered a modern poem for many reasons. Characteristics of modern poetry--specifically poetry from the early 20th century--include classical allusions, use of foreign language, open verse, juxtaposition, intertextuality, and often times the theme of disillusionment. This poem is open verse and contains all of these features, beginning with the opening quotation from Dante's Inferno in Italian. The poem also juxtaposes images throughout and incorporates intertextual elements like the references to Hamlet. The theme of disillusionment is evident in the narrator's frustration with his inability to make a bold move or even make a decision because he is unhappy with himself--an aging man who is balding and has skinny legs. He is so disillusioned, he cannot even bring himself to talk to women who are speaking of the great Michelangelo. Like most modern poems, Eliot's is high-brow and challenging to read--there are many references and allusions to explore.