Writing style

Rules for interface text.

• A button names its action with a verb, with no punctuation, joke or metaphor.
• Instructions start with the verb and stay on one line; the question is a separate element.
• Feedback headlines are one or two words. A wrong answer gets a correction or a next step, never blame.
• Error messages say what happened and what to do next.
• Offline messages say what is saved on the device and what syncs later.
• At most one exclamation mark per screen, and no emoji near lessons or sacred text.
• Address the learner without assuming gender; options in one list share the same grammatical form.
• One term per concept across the app.