Non-English AI Prompts: How to Prompt in Your Own Language

Non-English AI prompts work well in most widely used languages, and for most tasks you should simply write in the language you want the answer in. The old advice to “prompt in English and translate afterwards” is now needed far less than it used to be, but a handful of habits still separate good results from stiff, wrong-register ones: name the language and formality, give a sample sentence, and keep names and terms fixed.

This guide is for people who work in Lithuanian, Polish, German, Latvian, Estonian or any other language and want to know how to prompt an assistant such as Ask Mio so the output sounds like a native wrote it.

Should you prompt in English or in your own language?

It depends on the task, and the answer is more nuanced than either camp claims.

Prompt in your own language when

• The output is in that language: emails, posts, summaries, letters. The assistant picks up vocabulary and rhythm from your prompt.
• The task depends on local context: laws, institutions, idioms, place names, tax terms.
• You want the same register the prompt uses: polite, casual, technical.

Prompt in English when

• The task is technical and your language lacks settled terminology, such as debugging code or discussing model settings.
• You need the most detailed instruction-following for a complex, multi-part task, and you are comfortable in English.
• The output is going to English readers anyway.

Mix them deliberately

A very effective pattern is an English instruction with a target-language example: “Write a reminder about an unpaid invoice in Lithuanian. Formal address. Match the tone of this sample: [a sentence in Lithuanian].” The instruction is precise, and the sample fixes the language variety. Mio works in 25+ languages, so the same pattern applies to each of them.

Six controls for better non-English AI prompts

Almost every complaint about “robotic” non-English output comes down to something the prompt left open. Specify these six.

1. Language and variety. Name it: Brazilian or European Portuguese, Swiss or German German, Latin American or Castilian Spanish. Say “Lithuanian as used in Lithuania” if in doubt.
2. Formality and address. Many languages have formal and informal “you”: German Sie and du, Polish Pan/Pani versus ty, Lithuanian jūs versus tu. Choose one, or the assistant will guess.
3. Audience. Customers, colleagues, authorities, children. Register follows audience.
4. Locale details. Date format, decimal comma versus point, currency symbol position, quotation marks, address layout.
5. Terms to keep. Product names, brand names and legal terms that must not be translated or altered.
6. Length and structure. Some languages run longer than English for the same content; state a target.

Examples in three languages

The same task, an unpaid-invoice reminder, with the controls set. Have a native speaker check anything you send to customers.

German

“Schreibe eine freundliche Zahlungserinnerung für eine offene Rechnung. Anrede: Sie. Ton: höflich, sachlich, nicht drohend. Maximal 90 Wörter. Rechnungsnummer als Platzhalter lassen.”

Polish

“Napisz uprzejme przypomnienie o niezapłaconej fakturze. Zwracaj się do klienta per Pan/Pani. Ton: rzeczowy i życzliwy. Maksymalnie 90 słów. Numer faktury zostaw jako symbol zastępczy.”

Lithuanian

“Parašyk mandagų priminimą apie neapmokėtą sąskaitą faktūrą. Kreipkis į klientą „jūs“. Tonas: dalykiškas ir draugiškas. Ne daugiau kaip 90 žodžių. Sąskaitos numerį palik kaip vietos žymą.”

Each one sets the address form, tone, length and placeholder. If the output is still off, add one sentence of feedback in the same language, such as “shorter, and drop the apology”, and let the assistant revise. Our country guides on AI for German-language businesses, AI for Polish businesses and AI for Baltic languages go deeper on each market.

Prompt strategies compared

Strategy	Best for	Strength	Weakness
Whole prompt in your language	Everyday writing, local topics	Natural vocabulary and register	Weaker on very technical instructions in smaller languages
English instruction, target-language sample	Business writing with a set tone	Precise instructions, controlled tone	Requires a good sample
Prompt in English, ask for translation	Technical content, complex tasks	Strong reasoning on the English version	Translated text can sound literal
Draft in your language, ask for English	Sending text abroad	You control the meaning	Idioms need review
Generate, then native-speaker review	Anything customer-facing	Catches subtle errors	Costs time

Prompting for different kinds of text

The controls above stay the same, but their weight shifts with the kind of text you want.

Marketing and web copy

Give the assistant a sample of your existing voice and ask it to match it. Marketing text is where literal translations hurt most, because slogans and wordplay rarely survive a word-for-word move. Ask for two or three original options in the target language, not a translation of an English line, and pick one.

Business correspondence

Formality and standard phrases matter more than creativity. Many languages have fixed openings and closings in business letters; ask the assistant to use the conventional ones for your country and to keep sentences short. Check greetings and titles, since errors there are noticed instantly.

Summaries and reports

If you paste a document in one language and want the summary in another, say so and ask the assistant to keep names, figures and quoted passages exactly as written. Then compare the numbers. Summaries are where a quiet error, such as a wrong date or a swapped name, is most likely to slip through.

Learning and practice

Assistants are useful conversation partners for language learners: ask for corrections with short explanations, or for the same sentence in three registers. Be aware that a confident explanation can still be wrong on fine points of grammar, so confirm rules that matter in a reliable reference or with a teacher.

Where non-English output still goes wrong

Literal translation and calques

English structures sneak into other languages: phrases translated word for word, unnatural passive voice, “in order to” clauses. If the text feels foreign, ask: “Rewrite this the way a native copywriter would write it, not as a translation.”

Inflection and case

Languages with cases, such as Lithuanian, Latvian, Polish, Finnish and Estonian, change the ending of names and terms depending on the sentence. Assistants usually manage common words but can slip on rare names, company names and new terms. Read these carefully.

Wrong formality

A friendly informal “you” in a letter to a tax office is a mistake. Always set the address form, and check the output for slips halfway through.

Diacritics and characters

Letters such as ą, č, ę, ė, š, ž, ü and ß must survive copy and paste. If text arrives with wrong characters, the problem is usually encoding in the tool you pasted into, not the assistant; the Unicode Consortium’s standard is the reference for how characters are defined.

Facts about local rules

Laws, tax rates, deadlines and forms differ by country and change. Assistants may state outdated or foreign rules with confidence. Verify against the official source. Our explainer on AI hallucinations covers this failure and how to catch it.

Mixed-language text

Texts that mix languages, such as quotes in English inside a Polish report, may get “corrected” into one language. Tell the assistant to leave quoted passages untouched.

Quality by language: what to expect

Quality varies with how much training text exists for a language, and we do not publish rankings because they change with each model release and are easy to misquote. As a broad pattern, large languages with plenty of text tend to get the most fluent output; smaller languages usually still work, but with more errors in inflection, idiom and rare vocabulary. The practical response is simple: run a short test in your language on a task you know well, and note what it gets wrong. The EU’s own list of official languages is a useful reminder of how many languages a European business may meet in a single week.

Because Mio routes each request to a model suited to the task, quality can also differ between requests: a short chat reply and a long document may use different models. If something reads badly, rerun it or rephrase the request before concluding that your language is unsupported. The tone-and-quality question for translations specifically is covered in our guide to AI translation quality, and the broader picture in the multilingual AI assistant guide.

A step-by-step workflow for important texts

1. Write the brief in the language you are most exact in. Include audience, purpose, formality, length and locale.
2. Add a sample. One good paragraph in the target language does more than a paragraph of adjectives.
3. Generate once, then give feedback in the target language. Short corrections such as “less formal” or “shorter sentences” work well.
4. Ask for a checklist of doubtful spots. “List any terms, names or facts you are unsure about.”
5. Read aloud. Unnatural rhythm is easier to hear than to see.
6. Get a native reader for customer-facing text. Especially for smaller languages and legal or medical content.
7. Save what worked. Put the winning brief in a project’s instructions. In Mio, projects hold instructions and files, and memory keeps things like “always address customers with Sie”. You can see and control everything it stores.

Cost and plans

Mio prices requests by kind, not by language: a normal chat reply costs 1 point, a long or complex one 3, a coding answer 5 to 10 and an image 20. The free plan gives 600 points a month with Chat and Write, which is enough to test your language on real tasks. The Chat plan at €5 a month adds file uploads and Research, useful for translating or summarising documents, and includes 2,000 points. See the pricing page for all plans.

Common mistakes

• Leaving the formality open and getting a mix of du and Sie in one email.
• Asking for “good German” without saying which country or audience.
• Pasting a long English document and asking for “the same in Polish” with no glossary, so product terms get translated.
• Trusting numbers, dates and legal references in a translation without checking.
• Judging a language by one bad answer, or by one great one. Test several tasks.
• Skipping the native review because the text “looks fine”. Fluent-looking errors are the hardest to see.

For a wider view on language tags and how systems identify languages, the W3C’s guide to choosing language tags is helpful if you publish multilingual web content.

Frequently Asked Questions

Should I write AI prompts in English or my own language?

Use your own language when the output is in that language or depends on local context. Use English for technical instructions or complex multi-part tasks if you are comfortable in it. A mixed prompt, English instructions plus a target-language sample, is a strong middle path for business writing.

How do I get natural-sounding output in Lithuanian or Polish?

Name the language variety, set formal or informal address, state the audience and give a sample sentence. Ask for text “the way a native copywriter would write it, not as a translation”, then give short feedback in the same language and have a native speaker check important text.

Why does AI sometimes mix formal and informal address?

Because the prompt left it open, so the assistant guesses and can drift within a text. Specify the address form explicitly, such as Sie in German or Pan/Pani in Polish, and check the output for slips, especially in longer emails.

Is AI accurate for smaller European languages?

Often good, but less consistent than for the biggest languages, particularly with inflection, idioms and rare vocabulary. Test with your own tasks, review names and terms carefully and use a native reader for customer-facing or legal text.

Does prompting in another language cost more in Ask Mio?

Mio’s price list is by kind of request: 1 point for a normal reply, 3 for a long or complex one, 5 to 10 for code and 20 for an image. The free plan includes 600 points a month, so you can test your language without a card.

Can Ask Mio remember my preferred tone and address form?

Yes. You can tell Mio to remember preferences such as formality or house terms, or put them in a project’s instructions. You can see and control what is stored, and delete it whenever you like.

The Bottom Line

For non-English AI prompts, write in the language of the output, set formality and variety explicitly, give one sample sentence and fix your terms. Treat the result as a strong draft and get a native reader for anything customer-facing. To test it in your own language today, start with Ask Mio’s free plan, which needs no card and covers Chat and Write.