A dramatic writing knack I haven't seen discussed is what I'm going to call "the engineering of misunderstanding". It's very vital to a lot of drama--and more so comedies--and you get an ear for the guys that really do it right.

And sometimes you have to just fluff it all and hope you get away with it.

Basically, I'm talking about setups that depend on one person's actions or attitudes being depending on a misunderstanding of another character's actions of speech. The closer they move together, the tougher it is to rig up.

Naturally every screwball comedy or "Lucy" episode has the broad misunderstadings: the half-overheard phonecall, misinterpreted message, etc. I'm talking about something a little more substantial than that.

A masterpiece is seen in an excellent script: Nurse Betty. Betty is under the delusion that she is engaged to the doctor on a TV hospital sitcom and lights out to hook up with him. The closer she gets in--actually finding the hospital in L.A., for instance--the harder it gets for her not to get clued in. Finally she is actually on the shooting set of the show, face to face with the actor, but the writer keeps pulling rabbits out of his hat that enable her illusion to remain intact without straining belief or doing anything too ridiculous or contrived.

When you examine films with this in mind you start seeing many dialogues in which everything has to be excrutiatingly word-for-word in order to avoid having the people tumble to the fact that she's not really shacked up with the Count or he isn't really a fortune hunter or whatever.

A good example of one way such a confrontation is handled is when the dance instructor confront's Baby's father in "Dirty Dancing". Dad says, essentially, "I see an irresponsible womanizer who got his partner pregant, then abandoned her for an innocent younger girl."
All Swayze has to do is say, "Wait a minute, it wasn't ME who knocked her up," and our movie goes down the drain.
Instead, he huffs, "I guess that's what you would see." and stomps off, leaving the fallacious impression.
It's pretty hokey, really, but it flies.

Here's an example of a way such an interaction can get blown to pieces, yet still work, I think: In "Head In The Clouds", Gilda, whose been sleeping with a Nazi asshole, is confronted by the brother of a girl her SS boyfriend torured to death. She says, "You don't understand," and he kills her, a real punch in the gut because the character is about as perfect as you can imagine Theron could make her.
But all she had to do was say, "I was spying on the Nazi. You can check with...." Instead they cut.
Leaving, I would surmise, other who saw it like I was:"Jesus Christ, what a waste; all she had to do was say..."
But perhaps that's the intended effect?

Anyway, the purpose of this is to heighten awareness of such moments and not only the delicacy required to trip through the wires of perception, and some examples of how it can be slam-dunked, finessed, or simply lopped off and let the viewer stew in it.