How do you effectively use subtext in dialogue to add depth to your characters?

Get to the Bottom of the Unsaid
The subtext is about the meaning under the surface. Invent characters with layered motivations, for instance, that what they don’t say becomes as important as what they do. For instance, the character saying, "I am okay," but avoiding eye contact can suggest unresolved feelings.

Pro tip: observe how Hemingway's Iceberg Theory is used in dialogue writing.

Create Dialogue in Conflict
People often express one thing while their feelings are contrary to that. This natural counter position brings a sense of reality to the character. Think of a scene where the character says, "You did great" through clenched teeth. Prose can transform a simple phrase into a deeply engaged and suspense-filled scene.

Let the Place Develop Subtext
Nonverbal cues like body language and the environment are subtext. For example, a character's posture, such as sitting in a dark room, moving a trembling hand over a glass of bourbon, tells more than words could say.

Example: Even in Mad Men, Don Draper's hidden meanings are often translated through silence and glances during critical moments.

Build Anticipation with Silence
At times, it isn't about spoken words at all. Rather, throw in some sections that make the characters mere silence or confusion of utterance about it. Thus, amazement due to the talk artful voids is emotional depth creator.

Pro tip: Test your dialogue scenes with minimalistic lines, these being the opposite of your paraphrasing, until you get only the essential lines left out.

Share Hints as a Foreshadowing Strategy
Subtext is able to function in a far-reaching tool. A fleeting undercurrent in a dialogue can be a forerunner of the actual twist of events or secret facts.

Example: The Social Network, the marks of sarcasm Eduardo uses when talking about Mark act as foreshadowing discovery of their forthcoming problem with betrayal.

Trust the reader and the audience to fill in the blanks, and understand what's going on beneath the surface for the characters. We're all creatures of empathy. We will naturally put ourselves and into the characters' shoes. A trick I sometimes use is I'll have the characters say the OPPOSITE of what they're feeling. "I'm fine" when they're devastated. "I hate you" when they love them. Music is really about the space between the notes, and good dramatic writing is the same. 

If you MUST have an exposition dump - and sooner or later you'll find one is necessary - ensure there's enough happening around it. Deliver that exposition in an original, dynamic, way. 

Subtext in dialogue makes conversations feel real by allowing characters to say one thing while meaning another. Instead of stating emotions outright, subtext reveals them through tone, body language, and word choice. For example, if a character who just lost their job says, “Well, looks like I finally have time for that vacation,” their sarcasm masks disappointment, making the scene more engaging than if they simply said, “I’m upset.” This kind of indirect expression keeps audiences intrigued, forcing them to pick up on hidden emotions rather than being told outright.

A compelling example of subtext is in The Godfather, when Michael Corleone calmly says, “I’m going to make him an offer he can’t refuse.” On the surface, it sounds like a business deal, but the subtext is a deadly threat. The tension comes from what’s left unsaid, making the dialogue far more powerful. By weaving subtext into conversations, writers create layers of meaning, making characters feel complex and the story more immersive.