Sonnet 18William Shakespeare
Shall I compare thee to a summer's day?
The poem proposes a comparison, then dismantles it, and finally replaces nature with the poem itself as the thing that lasts.
← The devices guide
Metaphor and simile
Saying one thing is another (metaphor) or like another (simile). The interesting question is what the comparison transfers — which qualities move across, and what gets left behind.
How to spot it
For each comparison, name the two things joined and the one quality they share. If three qualities fit, the metaphor is doing more work than you thought.
Why writers use it
Because a new comparison makes the reader see a familiar thing as unfamiliar for a moment.
In the texts
Dover BeachMatthew Arnold
The Sea of Faith
A tide becomes belief, and the withdrawing roar becomes decline. The metaphor carries an entire historical argument.
The MetamorphosisFranz Kafka
Gregor wakes as an insect.
The comparison is never explained, which forces you to decide whether it stands for illness, uselessness or being a burden.
Common misread
Do not call every comparison a metaphor when it is a simile, and do not explain a metaphor until you have said what it makes you see.