Chat in English with someone who speaks Vietnamese

With Piou, you write in English and your contact writes in Vietnamese. With Piou Premium, every Vietnamese message appears in English on your phone, translated on the device itself, and the original, tone marks included, stays one tap away. For your contact to read you in Vietnamese, they need Premium too, or you can gift it to them.

How it works between English and Vietnamese

Piou detects the language of each message on the sender's phone and stores it exactly as written. Translation happens on the recipient's device, into the recipient's language: you read English, your grandmother reads Vietnamese, and nobody changes the way they type.

The engine depends on the device:

• iPhone: Apple's built-in translation, on iOS 18 or later.
• Android: ML Kit by Google, with models downloaded to the phone.
• Web app: the open source Bergamot engine with Firefox Translations models running in the browser, or Chrome's built-in translation on a computer when available. English and Vietnamese form a direct pair on the web.

A translated message carries the label Translated. Tap Show original to see exactly what was written, which helps with names, addresses and anything that reads oddly. Translations never leave your device; the messages themselves are stored on Piou's servers in their original language so they can be delivered and synced.

Language packs download once, ideally over Wi-Fi; after that, translation and Face to face mode work offline. The free plan is a complete messenger, with messages shown in their original language. Premium adds automatic translation, voice messages transcribed and translated, translated subtitles during calls and Face to face mode.

What an exchange looks like

Emily lives in San Jose. Her bà ngoại, her mother's mother, lives in Ho Chi Minh City and writes in Vietnamese. Here is roughly what each of them sees:

• Bà writes: “Con ơi, bà nghe mẹ nói con mới đi làm. Nhớ ăn uống đầy đủ nha con.” → Emily reads: “Son, Grandma heard from your mom that you just started working. Remember to eat properly.”
• Emily replies: “Thank you, Grandma! I'm eating well, don't worry. I'll video call you on Sunday at 8 pm my time.” → Bà reads: “Cảm ơn bà! Tôi ăn uống tốt, đừng lo. Tôi sẽ gọi video cho bà vào Chủ nhật lúc 8 giờ tối theo giờ của tôi.”

“Con” means “child” and says nothing about gender, so the translation guessed “son”. In the other direction, Emily's “I” became “tôi”, a neutral word that sounds stiff from a grandchild, who would say “con”. And “8 pm my time” on Sunday in California is 10 or 11 am on Monday in Vietnam: give both times when you plan a call.

Tips for chatting with Vietnamese speakers

• Age shapes the words. Vietnamese pronouns depend on age and relationship, so people may ask your age early on. It's how they choose the right way to address you, not nosiness.
• The given name comes last. In Nguyễn Thị Hạnh, Nguyễn is the family name and Hạnh the given name. Say “Ms. Hạnh” or “chị Hạnh”, not “Ms. Nguyễn”, especially since so many families share that name.
• Tone marks change meaning. Hạnh and Hành are different words. Copy names with their marks, especially for an address or a booking.
• Dạ, ạ and vâng. These small words of respect, common when speaking to elders, often disappear in translation. A message that reads flat may not have been flat at all.
• The lunar calendar. Tết, the Mid-Autumn Festival and death anniversaries (đám giỗ) follow the lunar calendar, so their dates shift every year. A message on those days means a lot.
• “Ăn cơm chưa?” “Have you eaten?” is often a warm hello, not a question about your lunch.

Where translation can stumble

• Kinship pronouns. Anh, chị or em can become “older brother” or “little sister”, and English “you” and “I” often turn into a cold “bạn” and “tôi”.
• Gender. “Em”, “con” and “nó” don't say whether someone is a boy or a girl, so the translation guesses. Add the name when it matters.
• Missing accents and shortcuts. Messages without tone marks, or with “ko” (không), “dc” (được) and “j” (gì), translate poorly.
• North and South. Some words change meaning: “ốm” means “sick” in the North and “thin” in the South. Strong regional accents also make voice messages harder to transcribe, and speech recognition depends on what each phone offers.
• Names that are words. Hoa (flower), Lan (orchid) or Phúc (blessing) may be translated as nouns.
• Amounts and mixed messages. “50k” means 50,000 dong and “1tr2” 1,200,000 dong. Sentences mixing Vietnamese and English often come out garbled.

Getting started

1. Install Piou on iPhone (iOS 18 or later) or Android (8.0 or later), or use the web app at app.piou.chat.
2. In Settings → Language & translation, choose English, then download English and Vietnamese, ideally over Wi-Fi.
3. Invite your family with a link, a QR code or from your address book. Help your grandparents set up Piou during a visit or a video call, and add a Vietnamese keyboard to their phone.
4. Start the 7-day free trial to turn on translation. A card is required, nothing is charged for 7 days, and the subscription then starts automatically at the price shown unless you cancel before the trial ends.
5. Want them to read you in Vietnamese? Use Gift Piou to someone: each person you gift counts as one subscription, and you manage gifts in Settings → Premium.