On-screen copy

Read when: writing a label, a button, help under a field, an empty state, a confirm dialog, a toast or a refusal, in Arabic or English, or adding translation keys. Owns: who each surface is written for, the length budget, punctuation, verb-only labels, the wording of confirms and danger zones, Arabic register, and the lang-file rules.

TL;DR

Short, plain, and only what the reader needs to act.
A button says the verb alone. The card title already carries the context.
Help under a field is one sentence of about twelve words.
State the rule, not the reasoning; the reasoning goes in a code comment beside the rule.
No em dashes, no semicolons, no "simply" or "please note" in UI text.
Nothing on a screen describes the screen it is printed on.
In a two-language app every string comes from the lang files, in both languages.

Who reads it

Surface	Reader	Register
product UI: labels, help, refusals, toasts	someone mid-task	the fewest words that let them act
a help guide	someone learning a screen	what a screen or setting means, in the words the screen uses
code comments	whoever changes the code next	the decision and why

The commonest failure is writing one surface's sentence on another: an argument for a design decision in a help line, addressed to someone who will never make that decision.

Budget

Surface	Budget
help under a field	one sentence, about 12 words
confirm dialog description	the consequence, and the way back if there is one
empty state description	one sentence naming the next action
panel or sheet subtitle	none: the content says it
toast	one clause

Cut in this order and stop at the first cut that leaves a true sentence:

What the placeholder already shows. A worked example teaches faster than a sentence about it.
What still happens ("every other check still runs"). It reassures the writer, not the reader.
Why the rule exists. That goes in the code comment.
A consequence nobody can act on. "This cannot be undone" earns its place on a delete; "this is recorded" does not when everything is.

A destructive confirm is the one place a second sentence earns its keep, and only for the way back: "Duplicate it first if you need the same lines again."

The screen already says it

An empty state's title already states the state, so the description only names the next action. If nothing survives the cut, drop the description: a title, an icon and the button is complete.
A subtitle describing the table beneath it says nothing the column headers do not.
What earns a line under a heading: a live value read from config, a fact the reader must meet before acting, or a consequence that is nowhere else on screen.

Labels and buttons

Where	Says	Not
a button	the verb alone: "Add", "Save", "Send"	"Create and configure the customer"
a field label in a titled card	the field alone: "Email"	"Billing contact email"
a confirm title	a question about the effect: "Delete this customer?"	"Are you sure?"
its description	the consequence and what survives it	the title again
a danger-zone description	what happens, one sentence, present tense	how it is implemented
a refusal	the next action, or who can take it	only what went wrong

Say the effect, not the mechanism: "The customer's history stays, but their access stops at once", not a sentence about soft-deleting a row.
Name the state before the action, so a section reads correctly whether the record is active, paused or failed.
Use the words the screen uses. A guide never names an internal key the UI does not show.
No warning that always shows.
Ends with a period: help lines, notes and descriptions, in Arabic as in English. Titles, labels and buttons never do.

Punctuation

No em dashes on screen: a sentence with one is two sentences, or one with commas.

Written	Read
Full — adding another is refused.	Full. Adding another is refused.
Every sign-in — and every refused one — is recorded.	Every sign-in, and every refused one, is recorded.

The same goes for semicolons, "simply", "please note", and a first clause that only introduces the second. They read as drafted rather than written.

Arabic

Write the Arabic first and plainly, in simple modern standard Arabic, not translated from an English sentence. Keep the technical words engineers use when there is no common Arabic one.
Buttons are verbal nouns: «إضافة»، «حفظ»، «إرسال»، «حذف».
A confirm title is a question: «هل تريد حذف هذا العميل؟»
A danger-zone description says what happens, in the present: «حذفه يوقف وصوله فورًا، ويبقى سجله.»
A Latin value inside an Arabic sentence is isolated so it keeps its order (rtl-and-bidi.md).

Lang files

An app with more than one language reads every string through t() (composables.md); a one-language app may write its copy in the templates.

Every key in every language, in the same change. A missing key shows the raw key on screen.
Group by area, in a fixed order: a file per area with title, fields, actions, messages, errors; words no area owns (Save, Cancel, Status) in common. An area never keeps its own copy of a common word.
Keys are snake_case; values are whole sentences with :placeholders. Never glue two keys into one sentence: Arabic word order differs.
A count is a label and the number ('rows' => 'Rows: :count'), which reads right for every number in both languages, instead of a sentence that needs plural forms.
The Form Request reads the same keys as the page (attributes(), messages()), so the label above a field and the word inside its error are one key.
Enum labels and validation messages are translated on the server and arrive in props or errors; Vue never builds an enum key.
A key built from a variable is fine only for a closed set in a group of its own (t(`invoices.kinds.${kind}`)).
Share only the files the UI reads. Every shared prop rides on every response.

Self-check

[ ] Buttons are verbs; labels in titled cards are bare.
[ ] Help one sentence; empty state names the next action; no subtitle restating the table.
[ ] No em dashes or semicolons; descriptions end with a period, titles do not.
[ ] Confirm title is a question about the effect; description gives the consequence.
[ ] Every key in every language; no glued sentences.