Vietnamese landing-page copy (vi-VN)

Vietnamese is a low-resource language for LLMs. Left unguided, output defaults to English-calqued translationese: fluent-sounding but obviously machine-written. It picks the wrong pronoun, translates CTAs word-for-word, writes illegal advertising superlatives, and formats currency the American way. Every rule below exists to stop a specific, observed defect.

Step 1 — Pick the register before writing a single word

Vietnamese has no neutral "you." The pronoun is the first decision, not a detail.

Audience	Address the reader as	Vocabulary
Real estate, finance, luxury, airlines, healthcare	`quý khách`	Hán-Việt heavy, ornate
Institutional, government, broadcast announcements	`quý vị`	Formal, plural
Sales consulting, mid-market services, local business	`anh/chị`	Warm, respectful
SaaS, tech, e-commerce, youth brands	`bạn`	Thuần Việt, terse
Policy, terms, descriptive prose (never direct address)	`khách hàng`	Neutral 3rd person

If the brief does not say, infer from the product. A căn hộ cao cấp page is

quý khách

. A developer tool is

bạn

. Never mix two registers in one page — that is the single most visible amateur tell.

Full pronoun matrix, including the registers the other Vietnamese skills use: references/register-matrix.md. The Hán-Việt vs thuần Việt prestige axis, classifiers, and the section-order house style: references/register-guide.md

Step 2 — Core rules (non-negotiable, no file hop needed)

Emit NFC Unicode. Precomposed
```
ế
```
(U+1EBF), never base + combining marks. NFD breaks web font rendering and string length. Normalize everything you output.
Pick one tone-mark style and hold it for the whole document. Default to kiểu mới (
```
hoà
```
,
```
thuỷ
```
,
```
khoẻ
```
) matching post-2022 Bộ GD&ĐT textbooks. Kiểu cũ (
```
hòa
```
,
```
thủy
```
,
```
khỏe
```
) is equally correct and still dominant commercially — match the client's existing site when there is one. Neither is wrong. Inconsistency within one page is the defect.
Modifier follows the noun.
```
căn hộ cao cấp
```
, never
```
cao cấp căn hộ
```
.

Recast English passives.

được thiết kế bởi X

→

do X thiết kế

, or make it active:

X kiến tạo

Never write
số 1
,
tốt nhất
,
duy nhất
,
hàng đầu
as an unproven claim. This is illegal under Điều 8 khoản 11 Luật Quảng cáo 16/2012/QH13, not merely tacky. Real fines, currently issued. See references/banned-phrases.md.
Vietnamese has no grammatical plural. ICU messages take only
```
other
```
. An
```
one {}
```
branch in
```
vi.json
```
is always a bug.
Write CTAs from the conventional list, not from the English.
```
Learn more
```
is
```
Tìm hiểu thêm
```
, never
```
Học thêm
```
.

Step 3 — Look up the conventional wording

Do not invent Vietnamese for a UI string that already has a settled convention. The EN→VI table covers CTAs, nav labels, form fields, and the standardized real-estate section names (

Tổng quan dự án

Vị trí

Tiện ích

Mặt bằng

Tiến độ

Chính sách bán hàng

Chủ đầu tư

Pháp lý

references/glossary.md

Step 4 — Format numbers, dates, and locale data correctly

VND groups with periods and decimalizes with commas:

2.500.000 ₫

. Real-estate prices are colloquial:

Chỉ từ 2,5 tỷ

35 triệu/m²

. Dates are

dd/MM/yyyy

. Phones are

0xxx xxx xxx

+84

. Addresses run small-to-large. Slugs are unaccented, lowercase, hyphenated.

references/locale-formatting.md — also covers

Intl.NumberFormat('vi-VN')

, BCP-47 tags, font subsets and stacked-diacritic typography, and the accented/unaccented dual-keyword SEO rule. The NFC and tone-mark rules behind points 1 and 2 above are in references/unicode-and-tone.md.

Step 5 — Get the legal copy right

Lead forms are regulated. Nghị định 13/2023/NĐ-CP requires express, informed, revocable consent with a stated purpose and a linked

Chính sách bảo mật

. Advertising superlatives require documented proof.

references/legal-copy.md and references/banned-phrases.md for the landing-page specifics; references/compliance.md for the cross-cutting advertising, consent, promotion and anti-spam rules every Vietnamese skill shares.

Step 6 — Validate, fix, then ship

Run the validator immediately after writing. If it reports errors, fix them and run again. Only present the copy once it passes. Do not skip this because the output "looks fine" — NFC violations and comma-grouped numbers are invisible to reading.

bash

python scripts/validate_copy.py path/to/copy.md --register re

```
--register re|saas|formal|consult
```
enables the register-consistency check.
Exit
```
0
```
= clean or warnings only. Exit
```
1
```
= errors that must be fixed.
```
--json
```
for machine-readable findings;
```
--strict
```
to fail on warnings too.
```
--fix
```
rewrites NFC violations in place; every other rule is a human judgement call.

Check glyph coverage when a specific web font is specified:

bash

python scripts/check_font_coverage.py path/to/copy.md

If a flagged superlative is backed by a licensed market survey or award certificate, keep it and annotate the source instead of deleting it:

markdown

Thương hiệu số 1 Việt Nam <!-- proof: Khảo sát Nielsen VN 2026, chứng chỉ số 123/NS -->

Step 7 — Learn from the worked pairs

Before writing anything long, read the bad→good corpus. Each pair names which failure mode it fixes, and the diagnosis generalizes further than the string does.

references/examples.md

For structured localization files, start from assets/vi.json.template — next-intl shaped, both registers,

other

-only plurals.

For human review before publishing: references/qa-checklist.md

Quick self-check

Before returning Vietnamese copy, confirm:

One register throughout; the pronoun matches the audience.
Every CTA is from the glossary, not translated fresh.
No unproven superlative anywhere on the page.
Prices grouped with
```
.
```
, decimals with
```
,
```
,
```
₫
```
or
```
tỷ
```
/
```
triệu
```
colloquial form.
Dates
```
dd/MM/yyyy
```
, phones
```
0xxx
```
/
```
+84
```
, address small-to-large.
One tone-mark style, consistently.
Lead form has a consent checkbox, a purpose statement, and a privacy-policy link.
```
validate_copy.py
```
exits clean.

vietnamese-landing-copy

NPX Install

Tags

SKILL.md Content