Universal sentence-level principles that apply to every customer-facing format. Pairs with copywriting-mastery (practitioner-specific moves) and design-thinking-for-content (structure).
Source synthesis: Harry Dry (Marketing Examples), Strunk + White, William Zinsser, George Saunders, Verlyn Klinkenborg. Operator cards for these voices are pending future ingest from primary sources.
Three quality tests
Apply to every sentence.
1. Visualization test (Harry Dry). If the reader cannot picture it, they will not remember it. Zoom in until you reach something concrete. "Unlock productivity" → "Reps make 50 calls instead of 15."
2. Falsifiability test. If a claim cannot be proven true or false, it has no persuasive power. "Unlock your brain's superpowers" → "One capsule equals six hours of focus." Every benefit must be testable.
3. Uniqueness test. "Never write an ad a competitor can sign." If a competitor could lift the sentence for their product, it has no differentiation value. Cut it or rewrite with specific proof.
Sentence-level craft
Economy
- Target: under 25 words per sentence.
- Cut filler: "in order to" → "to"; "at this point in time" → "now"; "due to the fact that" → "because."
- Cut qualifiers: really, very, quite, somewhat, actually, basically.
- One idea per sentence.
Active voice
Default to active. Subject does the verb. Ctrl-F "by" to find passive constructions and rewrite. Passive is fine when the actor is unknown or unimportant.
Concrete > abstract
Specific nouns. Specific numbers. Named entities. Replace categorical words with the closest concrete instance.
Verbs over modifiers
Strong verbs carry sentences. "Walk slowly" → "amble." "Look quickly" → "glance." Adverbs are usually evidence the verb is weak.
Rhythm
Vary sentence length. Short. Then medium length to give a thought room. Then longer constructions that expand the breath. The pattern is what makes prose readable.
Six formulas
1. PAS: Pain, Agitate, Solution. Short copy.
2. AIDA: Attention, Interest, Desire, Action. Long copy.
3. 4Ps: Picture, Promise, Prove, Push.
4. BAB: Before, After, Bridge.
5. FAB: Features, Advantages, Benefits.
6. 3W: What it is, Why it matters, So what outcome.
Empty-modifier blocklist
Delete on sight: powerful, robust, seamless, cutting-edge, innovative, comprehensive, world-class, best-in-class, next-generation, revolutionary, holistic, leverage (as verb), unlock (as verb), transform.
Voice rules
- "You" not "we" — buyer as agent.
- Conversational — write like you talk to a smart friend.
- Specific — names, numbers, places.
- Honest — concede limits before they're asked.
- Cut throat-clearing openers ("In today's fast-paced world...").
CTA craft
- One primary CTA per section.
- Verb that matches what happens on click. "Book a demo" if it books a demo.
- Repeat the CTA throughout the page.
- Risk-reversal copy near the CTA reduces friction.
Quality gates
- Every sentence passes visualization, falsifiability, and uniqueness tests.
- No empty modifiers from the blocklist.
- Active voice throughout.
- Single CTA per section, or clear primary/secondary hierarchy.
Common failure modes
- Feature dumping without benefit translation.
- "We" language instead of "you" language.
- Clever over clear.
- Vague claims that could apply to any product.
- Multiple competing CTAs with no hierarchy.
- Addressing multiple audiences in one piece.
- Rounding numbers ("over 60%") instead of citing the exact figure.
- Mixing voice across sections (formal hero, casual body).