Look at how well my sister and I are juxtaposed. Despite our matching attire, we had very different personalities. Not opposite; just different. Growing up, comparisons were often made by teachers; not only with looks, but with behavior. (She was way more behaved than me.)

Juxtaposition is a literary device that clues the reader into the contrasts between characters, concepts, and places. By drawing comparisons between two dissimilar things/concepts/people/places, writers can create a vivid picture in the mind of the reader. When I looked up some concrete examples of this, the same darn ones kept coming up. I didn’t want to regurgitate them, but they really are great examples.

Characters: John Milton’s narrative poem, “Paradise Lost.” In it, Milton places good and evil (God and Satan) side-by-side, in order to showcase the contrast, thus, making Satan’s inevitable exodus below ground, a reasonable conclusion. 

Concepts: Shakespeare was a juxtaposition genius and there were several examples of this in his work. This part, from Romeo Juliet, Will wanted to show the contrast between “light” and “dark.” He is wanting to show that despite the darkness of night, Juliet ‘s face radiates against the skin of an African: 

“O, she doth teach the torches to burn bright!
It seems she hangs upon the cheek of night
Like a rich jewel in an Ethiope’s ear;” 

Place: Charles Dickens does this in A Tale of Two Cities:

“It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to Heaven, we were all going direct the other way…”

(source)

I did come up with a few examples on my own, that are more modern. In the Harry Potter books, readers are aware of the good vs. evil concept, and Rowling does a great job of doing that, by subtly placing Harry and Volemort side-by-side. Harry has a nightmare where he faces several doors, but then the scar on his forehead burns. The reader surmises/is reminded that it is the work of Voldemort. 

Stephen King is also a master of juxtaposition. In Cujo, we see the marked contrast with this vicious, killer canine and the everyday suburban life. In Secret Window, King places us in a quiet, idyllic setting with the tortured, chaotic soul of a writer. (Which is another thing he got right.) 

You follow me?

Common proverbs in the English language make use of juxtaposition:
You can’t teach an old dog new tricks.
All’s fair in love and war.
Make a mountain out of a molehill.
When the cat’s away, the mice will play.

Other ways things to compare:
Young and old
Funny and sad
Warm and cold (as in emotions or personalities)
Pious and atheism
Clean and dirty (such in The Odd Couple, or prude vs. not-so prude )

You don’t have to beat the reader over the head with these differences; being subtle and consistent can be enough to show what you’re trying to get across to the reader.

Do you use juxtaposition in your own writing? If so, how?