Do You Make These Mistakes in English?" - Sherwin Cody School of English (Mid-Week Pictorial, Dec 7 1929)
The pattern
This still is filed under If-then promise.
Define
A conditional contract: if you do this, you get that. The sentence can be tested against the reader's own case.
Mechanism
Specificity does the persuading. The if names the action. The then names the outcome. Hedging kills it.
Verdict
We can name both the action and the result without adjectives
Why it works
This is the 1922 page rebuilt with proof stacked on top of it: the same headline, the same self-diagnosis opening, but now a seven-year-old control carrying a user count, a named third-party demonstration in a real school system, and three hard numbers. The word These still does the essential work, promising a closed list of faults rather than an open indictment. The strongest passage is the standing-at-your-elbow conceit, which makes an abstract product - a correspondence drill - into a physical experience the reader can picture, and it is careful to say the mentor would not laugh at you, which handles the shame objection directly. Naming that the device finds your mistakes and ignores what you already know converts the reader's biggest cost objection, time, into the product's main feature.
Steal this when
You have a headline or lead that is already proven and you are re-running it after the product has accumulated evidence. Keep the headline and the opening demonstration untouched, and spend the new space on named third-party results, user counts and hard numbers rather than rewriting the hook.