Screenwriting : Five Dialogue Sins That Instantly Weaken a Script by Tash Smurthwaite

When reading scripts, dialogue is often the deciding factor between a screenplay that sings and one that falls flat. Great dialogue feels effortless: it reveals character, builds tension, and moves the story forward. Weak dialogue, however, has a way of clanging loudly on the page.

Here are a few common dialogue pitfalls that can pull readers straight out of a script:

1. Overused Stock Phrases:

Lines like “I can explain,” “I can’t unsee that,” or “And by X, I mean Y” appear so often they’ve become creative wallpaper. They’re not wrong, but they feel predictable. Dialogue should feel specific to the character saying it.

2. Every Character Sounds the Same:

If you covered the character names in your script, could you still tell who was speaking? Strong writing gives each character a distinct voice. The Coen Brothers are great at this. On Raising Arizona, they reportedly shaped each character’s speech around what that person might read, whether the Bible or trashy magazines. The result is a world where every voice feels unique.

3. Exposition Disguised as Conversation:

“As you know, we’ve been partners for fifteen years…”

Characters rarely explain shared history to each other in real life. Information should emerge through conflict, emotion, and subtext, not polite briefings for the audience.

4. The “Garden Birds” Problem:

Writer John O’Farrell once described a pre-war joke about a listener complaining to the BBC after hearing the phrase “tits like coconuts” on the radio. The BBC replied that if he’d kept listening he would have heard the rest of the sentence: “…while sparrows like breadcrumbs, for the talk had been of garden birds.”

The joke lands on “breadcrumbs.” Everything after that simply explains the punchline the audience has already understood. Dialogue should trust the audience. Once the moment lands, move on.

5. Repeating What the Audience Already Knows:

Film is a visual medium. If the audience can already see or infer something, the dialogue doesn’t need to underline it again. Mad Men is a great example of letting the audience catch-up and not over explaining things.

Even with a strong concept and structure, weak dialogue can make a script feel flat. Sometimes what a screenplay needs most is a focused dialogue pass: sharpening character voices and cutting lines that aren’t pulling their weight. If you’d like help strengthening the dialogue in your own scripts, it’s something I work on regularly with writers through my site: https://scriptservices.co.uk

One useful exercise I often recommend is a simple table read (if you can enlist family and friends to get involved!). Hearing different people read each role out loud quickly reveals clunky or unnatural dialogue that might seem fine on the page.