"Bent double, like old beggars under sacks" This simile introduces the exhausted mental and physical state of a troop of soldiers after returning from the frontlines. Shows the awful impact that war has had on these once healthy men, and forces the reader to feel horrified and shocked at their expense.
"Drunk with fatigue; deaf even to the hootsOf gas-shells dropping softly behind." Shows the sheer exhaustion these men felt, how they had become accustomed to death and destruction. This proves many pro-war poets wrong, as we learn it is not honourable or glorious to die in these battlefields. Due to advances in modern weaponry, soldiers could not see their assailiants, which took out the humanity of the battle.
The simile "And flound'ring like a man in fire or lime" allows the reader to imagine the graphic scene of the young soldier dying in the gas attack, and we feel his desperation to survive. This highlights how this soldier was barely a boy and he should not have been subject to war in the first place.
Owen's words "If you could hear, at every jolt, the blood Come gargling from the froth-corrupted lungs," emphasises the effect that war had on it's soldiers as his death was unimaginable and likely traumatised many witnesses. This was no game - this was life or death, despite the way the media glorified warfare.
The personal pronoun in"My friend, you would not tell with such high zest To children ardent for some desperate glory," targets the pro-war poets that had never experienced war themselves and reveal the truth. The children in this line are actually soldiers, many of whom were children, that felt inclined to enlist due to society's expectations and the white feather women awarded cowards.
Owen incorporates the ironically dead language Latin "The old Lie: Dulce et decorum est Pro patria mori." as a dig at the officers because the upperclass spoke Latin. Owen wanted the rich and fortunate to stop telling the helpless that going to war was an honour.