Wilfred Owen's "Dulce et Decorum Est" is a description of a gas attack suffered by a group of soldiers in World War One. By using shifting rhythms, dramatic description, and imagery, the speaker tries to convince readers that the horror of war outweighs the patriotic duty to war.
In the first stanza the speaker describes the calm before the gas attack. The speaker uses alliteration, "bent beggars," and onomatopoeia "cough" to create a sense of despair. The speaker uses assonance and alliteration in "Men marched asleep" to emphasize the falling rhythm of the exhausted men. The speaker then personifies the "Five Nines" as tired. The stanza ends with an ironic twist of the quiet sounds of "Five Nines" dropping softly behind.
The second stanza is full of action. The speaker uses the oxymoron "ecstasy of fumbling," to describe the controlled panic of the soldiers. The speaker uses onomatopoeia, "yelling stumbling drowning," to illustrate the pain and suffering the soldier went through before he died.
The two lines in the third stanza further emphasize the nightmares these events continue to cause for the speaker. The speaker uses cacophony, "guttering, choking, drowning," to convey the pain and suffering the soldier had to endure while dying from the toxic gas.
In the last stanza the speaker becomes more unrelenting as he continues to speak in iambic pentameter. The speaker uses strong imagery, "white eyes writhing," and onomatopoeia "gargling" of blood choked lungs, to convey the horror of war. The speaker uses a simile, "like a devil's sick of sin," to describe the face of the suffering soldier.