There are two main types of comparisons, the metaphor and the simile.
A metaphor directly equates two things. They state that something *is* something else.
Jack was a pig. (Assuming you are not writing fantasy in which Jack really is a talking pig, or transfigured into a pig.) Metaphorically, we understand that Jack is sloppy. The key to such comparisons is a shared cultural reference. If the reader doesn't understand that pigs wallow in mud, than the reader is left trying to figure out the ways in which Jack is porcine. (That's where some context comes in.)
A simile is a comparison that uses 'like' or 'as' to show how one thing is like another.
Sally ate like a bird. This simile gives us more context. We know it has to do with how Sally eats in some relation to how a bird eats. This is actually an interesting simile because it works based on an assumption that birds don't eat a lot. As related to people, it is meant to show that someone picks at his or her food. In fact, birds do eat quite a lot in terms of their body weight--they just do it one seed or worm at a time. So another example where shared context drives the meaning of the comparison.
Pretty straightforward so far. For examples, I am going to use some of Shakespeare's sonnets and some of my own poetry. This is not to imply that I am comparing myself to the Bard in any way. It is a matter of convenience vis a vis copyright. Good old Willie's work is in the public domain. I grant myself permission to use my own words. No problem. :)
Here is another of Shakespeare's most well known sonnets. If we look at the lines in bold, we see an extended simile:
When the narrator thinks about his love, it makes him sing like a lark and feel happy.
But there is also subtle metaphor: In the line highlighted in italics, we see that he equates the love he receives with the wealth of kings.
When in disgrace with fortune and men's eyes
I all alone beweep my outcast state,
And trouble deaf heaven with my bootless cries,
And look upon myself, and curse my fate,
Wishing me like to one more rich in hope,
Featured like him, like him with friends possessed,
Desiring this man's art, and that man's scope,
With what I most enjoy contented least;
Yet in these thoughts my self almost despising,
Haply I think on thee, and then my state,
Like to the lark at break of day arising
From sullen earth, sings hymns at heaven's gate;
For thy sweet love remembered such wealth brings
That then I scorn to change my state with kings.
Using more modern poetry, an example from my own writing:
Beneath my feet, only concrete. Cylinders,
rectangles, sand castles at the mercy
of no arbitrary tide. Squares striped
by ooze of asphalt, dwarf trees
armored against the spash of urine from lifted
hind legs. My heels strike sparks against the flint
of brick. The cobbler speaks hammer
and awl, calls these shoes by name.
I translate taxi, the fricatives of honks
and squeals. Shake this snow
globe city and ticker tape ribbons the air.
Soldiers return from every war to steam
grate medals. In the canyons and arroyos
of Spanish Harlem, wolf whistles salsa
the streets, buttered with black
beans and cigarillos. Parked cars turn sidewalks
into dance halls, each corner a new beat.
Along the park, staid ladies wearing
crenelated crowns lean into the greenery,
raise eyebrows over midriffs and tattoos,
gossip about naked ankles below bathing dresses.
Each decade's scandals thrill more
than the last. Workmen sprout
on scaffold trellises, swearing like sailors
who make love in twenty different languages.
Ivy digs its fingers into dusty mortar joints
setting pitons deep into the conquest
of up. I cannot name each plant whose roots
subvert the pavement, whose fruits seduce
me from farmer's stalls but I know
what I crave. I gulp whole crowds,
fresh berries burgled from the beaks
of starlings on this crackling sidewalk,
this unconducted symphony, this movable feast.
This piece is pretty much one extended metaphor. I highlighted many of them in bold, and the one simile in italics. Many of the metaphors are a specific subset of metaphorical language: personification. That is the grafting of human characteristics on something not human. In this piece, the ivy is a mountain climber setting pitons in the concrete for example, or the old buildings around central park 'staid ladies'.
The descriptive language using strong comparisons keeps the writing lively and immediate.
You can use these techniques to good effect in narrative. In fact, I remember reading George Lucas' original Star Wars novel (mumble mumble) years ago as a teenager. I haven't looked at the book in decades, but I *still* remember a turn of phrase he used, probably on page one. Something about space ships attaching themselves like rainbow ramoras to a larger, unwilling host. That image has stayed with me for more than 30 years. Pretty effective, no?
Another way to use comparisons to good effect in novels is to have your character use comparisons from his or her worldview/culture. In 'Heal Thyself', Lilliane is from a coastal community and a guild-based meritocracy. Zev is from a nomadic, desert culture with a fundamentalist religion. Among other differences in world view, Lilliane uses maritime similes and metaphors. Zev uses desert and predator/prey comparisons.
Zev slid to the floor, grateful they’d stopped moving. He was sweating and his legs were trembling as if he’d traveled hours on shifting sand.
It would be simpler if she could direct all her anger and frustration at him. Even if she’d known her course would bring her here, she wouldn’t have altered sail or tiller. Couldn’t have and still remain true to her art. Once he became her patient, it didn’t matter what Hal Jahnissim had done. Once she agreed to treat him, every current beached her on the same shoal.
Using culturally appropriate comparisons helps your world come to life and gives your characters a distinctive voice.
In comments, feel free to share a metaphor or simile from your writing, or re-write a comparison from your main character's POV.
A housekeeping note: Winners of the daily private critique will be chosen after the workshop is finished on Friday, so that anyone who wishes to participate will have that opportunity.