“Dulce Et Decorum Est” uses alternating rhymes throughout, resulting in a rhyme scheme that runs ABAB CDCD EFEF, and so on. The rhyme pairs in the poem are all exact, and most of them are so-called “masculine” rhymes, meaning that they occur on the final stressed syllable of the line. Owen’s use of a regular rhyme scheme consisting primarily of exact masculine rhyme is, on the surface, very traditional. This type of rhyme scheme was indeed very typical among poets of the eighteenth and nineteenth centuries. By the early twentieth century, however, many English-language poets came to find rhyme excessively formal and artificial, so they began to experiment with unrhymed verse. Given that Owen wrote the poem in 1917, his use of such a traditional rhyme scheme may seem old-fashioned. However, it’s also possible to interpret his use of rhyme as expressing a degree of irony. The poem’s main thematic concern isn’t simply that war is senseless. More pointedly, the speaker is contesting the old-fashioned ideal that it’s noble to die for one’s country. From this vantage, it’s possible to hear the rhymes in the poem as outmoded and ironic—a pleasant “chiming” that clashes with the poem’s images of traumatic violence.

The only times when Owen diverges from simple masculine rhyme, he does so with specific effects in mind. For example, consider the rhyme scheme in lines 9–12:

Gas! GAS! Quick, boys!—An ecstasy of fumbling
Fitting the clumsy helmets just in time,
But someone still was yelling out and stumbling
And flound’ring like a man in fire or lime.—

In these lines, the speaker describes the chaos and confusion that arises when a canister of poison gas lands nearby and sends the men of his unit scrambling. Owen subtly emphasizes the confusion by creating a so-called “feminine” rhyme with the words “fum-bling” and “stum-bling.” The extra unstressed -bling at the end of these words evokes the very sensation of fumbling and stumbling that the speaker describes. Another instance of feminine rhyme occurs in the lines that immediately follow (lines 13–16):

Dim through the misty panes and thick green light,
As under a green sea, I saw him drowning.

In all my dreams before my helpless sight,
He plunges at me, guttering, choking, drowning.

Here, the pairing of “drowning” with “drowning” isn’t just feminine; it’s also an example of identical rhyme, meaning that Owen has made a single word rhyme with itself. The repetition of the same two-syllable word has the effect of suspending time in the poem, indicating that the speaker is caught in a traumatic memory of this dying man. Significantly, the repetition of “drowning” also indicates a shift in the poem’s timeframe, as the speaker’s mind moves from the past to the present.