Ex. the first stanza of The Second Coming by Yeats:
Turning and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.
vs it rewritten in regular iambic pentameter:
The falcon turns and turns in a wider gyre.
He cannot hear the cry of the falconer.
The center of the cosmos cannot hold.
Mere anarchy is let loose on the world.
The tide that's dimmed by blood is loosed.
The ritual of innocence is drowned.
The best have lost their firm convictions.
The worst are full of fierce intensity.
- via Carl Dennis