Another Note on practical dialogue technique!
This week's Note is about repeating dialogue. As simple as this might sound, saying the same thing twice is an efficient way to make your story more interesting.
Switching Roles

The technique of repeating dialogue is called Dialogue Reversal. Basically, it works like this. Suppose you have two characters: A and B. Character A says something to character B early in the story. And then, later on, character B says the same exact line to character A, switching the roles between the two characters.
In Avengers: Infinity War (2018), Captain America took the moral high ground by saying "We don't trade lives" to Vision after he offered his own life to save the world. And then, much later on the story, their roles changed and Vision repeated the same line to Captain America after he told Vision to run.
It's a bit ironic and it also makes a seemingly simple line at the beginning of the story more meaningful.
Why use it?

It's a good statement for character developments. It helps to point out the changes that a character had gone through. Take Toy Story (1995), for example. At the beginning of the story, Buzz believes that he's a real space ranger and he can fly. Woody pointed this out by saying:
Woody: "That wasn't flying. That was falling with styles."
Then later on, after accepting the truth that he is actually just a toy, Buzz utters the same words that Woody use:
Buzz: "This isn't flying. This is falling with styles."
Reversing the roles between them and showing us that Buzz is not the same character that we first saw in the beginning.
The possibilities are limitless with this technique! Here are some notable examples that I find interesting.
Make It Meaningful!

In Amazing Spider-Man 2 (2014), Gwen Stacy gave a graduation speech at the beginning of the movie. Most of us would probably feel nothing about it, at first. And then, after Gwen died, Peter played the recording of that speech and suddenly it became something more meaningful than just a graduation speech. You might even shed tears during this moment. I certainly did.
Same line, but more powerful.
It's usually called Meaningful Echo. There's no role switch involved in this example, but the concept is still similar to Dialogue Reversal.
Make It Fun!

In a Spongebob Squarepants episode, One Krabs Trash (2002), Mr. Krabs made fun of Squidward when he's putting flowers on a grave labeled "Squidward's Hopes and Dreams". He said, "What a baby." And then at the end of the episode, Squidward saw Mr. Krabs crying in the street and said the same line: "What a baby."
It adds a fun little comedic effect to close the story. This one is called Gag Echo. You can read more about it here.
That's all for now!