Speaker
The poem's speaker, as the title informs us, is Aengus—an Irish god of youth, love, and summertime. In the poem, Aengus is burdened by an unrequited love, and spends years wandering the earth in search of the elusive woman he seeks. However, he maintains a surprising optimism, convinced in spite of his long, unsuccessful sojourn that he will eventually be successful in finding this longed-for lover. Yeats depicts him, in other words, as a long-suffering but paradoxically happy romantic. He is also happy and at home in the natural world, using a tree branch and berries to create a fishing rod, and imagining himself picking the sun and moon like apples.
The Girl
When the speaker catches a fish, the fish transforms suddenly into a mysterious woman. Almost nothing is revealed to us about the woman: she wears apple blossoms in her hair, calls the speaker's name, and then disappears, remaining unfound for the remainder of the poem. In spite of, or perhaps because of, her elusiveness and the lack of information surrounding her, the poem's speaker is fascinated by and fixated on the girl. By choosing to illustrate her with a few vivid but sparse details, but refraining from providing any additional information, Yeats creates an eerie mystique and suspense around her, which in turn drives the poem forward.
