Key Takeaways
- Asking for 'Chinese' is ambiguous, so models often default to Simplified script and mainland vocabulary.
- Gemini, Microsoft 365 Copilot and Perplexity all have a persistent setting where one language rule fixes every new chat.
- Gemini personal and Gemini in Workspace use two different settings pages, so work accounts need their own rule.
- Script converters such as OpenCC fix characters, not wording; your rule still has to name Hong Kong vocabulary.
You ask Gemini for a staff notice, paste in a supplier's email, and the draft comes back in Simplified Chinese. Or it is in Traditional characters but reads like a mainland press release, with words a Hong Kong reader would never use.
What do you need before fixing AI Chinese output?
You need ten minutes, access to the settings of each AI tool your team uses, and one written language rule. No paid upgrade is required: Gemini lets every user add instructions, Microsoft 365 Copilot Chat has custom instructions, and Perplexity has a preferred response language in its profile.
| Tool | Persistent language rule? | Where to set it | Usable in Hong Kong? |
|---|---|---|---|
| Gemini app (personal Google account) | Yes, Instructions for Gemini | gemini.google.com > Menu > Settings > Personal Intelligence > Instructions for Gemini > Add + | Yes, opened to Hong Kong users from March 2026 |
| Gemini in Workspace (Gmail, Docs, Sheets, Slides, Drive, Chat) | Yes, separate from the app | Gemini side panel > Menu > Settings > Personalization | Yes, on Workspace plans that include Gemini |
| Microsoft 365 Copilot Chat | Yes, Custom instructions | m365.cloud.microsoft/chat > ... Settings and more > Chat settings > Personalization > Custom instructions > Edit instructions | Yes, with a Microsoft 365 work account |
| Perplexity | Yes, Preferred response language plus profile text | Settings > Profile > Preferred response language; then activate the AI Profile | Yes |
| n8n, Zapier, Make AI steps | Only per step | The system prompt or instructions field of each AI step | Yes |
Sources: Google Gemini Help, Google Workspace Updates, Microsoft Support, Perplexity Help and Hong Kong Free Press on the Hong Kong launch.
Why does AI switch to Simplified Chinese?
Most models treat 'Chinese' as one language with Simplified as the common default. When your prompt is in English, or you paste mainland source text, the model follows that signal. Even in Traditional script it picks the most frequent wording in its training data, which is usually mainland or Taiwan usage, not Hong Kong usage.
The three triggers we see most
- English prompt, Chinese output: 'write this in Chinese' does not say which script or which region.
- Pasted source text: a Simplified press release or a mainland supplier's email pulls the reply into the same script.
- Search answers: Perplexity and Gemini with search quote whatever sources rank, so mainland or Taiwan wording leaks in.
How do you set a permanent language rule in Gemini?
On gemini.google.com open Menu, then Settings, Personal Intelligence, Instructions for Gemini, tap Add +, paste your rule and Submit. Google says all users can add instructions, though memory itself is US-only. Work and school accounts cannot use this page; they set the rule in the Workspace side panel instead.
Gemini app, personal account
- Step 1: Go to gemini.google.com and sign in with your personal Google account.
- Step 2: Menu > Settings > Personal Intelligence > Instructions for Gemini.
- Step 3: Tap Add +, paste the rule from the next section, tap Submit.
- Step 4: Check the Instructions for Gemini toggle at the top is on.
Gemini in Gmail, Docs, Sheets, Slides, Drive and Chat
According to Google's 2 September 2026 update, Workspace keeps its own instructions. Open the Gemini side panel, then Menu > Settings > Personalization, or simply tell Gemini in the panel to remember the rule. There is no admin switch for this feature, so every staff member sets it once.
Per Google's help page, instructions last up to 18 months, so add a calendar reminder to re-check them.
How do you set it in Microsoft 365 Copilot and Perplexity?
In Copilot Chat choose ... Settings and more, then Chat settings, Personalization, Custom instructions, Edit instructions, paste the rule and save. In Perplexity open Settings, then Profile, set Preferred response language, add the rule to your profile text and press Activate so the profile is actually applied.
Microsoft 365 Copilot Chat
- Step 1: Open m365.cloud.microsoft/chat with your work account.
- Step 2: Top right, ... Settings and more > Chat settings.
- Step 3: Personalization > Custom instructions tile > Edit instructions.
- Step 4: Paste the rule and select Save instructions.
If the tile is greyed out, your IT admin may have switched personalization off; ask them (Microsoft Support).
Perplexity
Perplexity answers in the language of your question by default. In Settings > Profile, set Preferred response language, write your Hong Kong rule in the profile text, and press Activate. Per Perplexity's help page, an inactive profile is the usual reason preferences are ignored.
What language rule should you paste?
Paste one short rule that names the script, the region and the register: Traditional Chinese for Hong Kong, formal written Chinese unless you ask for Cantonese, and a short list of Hong Kong terms. Naming the region matters more than naming the script, because Traditional alone still allows Taiwan wording.
Language rule (paste into the instructions field):
When I ask for Chinese, always reply in Traditional Chinese as used in Hong Kong (zh-HK), even if my prompt is in English or I paste Simplified Chinese text.
Use formal written Chinese, not Cantonese colloquial, unless I say [Cantonese for social media].
Use Hong Kong wording, not mainland or Taiwan wording. Examples: [add 5 to 10 terms your team cares about].
Keep English product names, prices in HK$ and dates as [DD Month YYYY].
If a source is in Simplified Chinese, translate its meaning; do not copy its wording.What goes wrong and how do you fix it?
The three failures we see: the rule is set in the Gemini app but staff work in Gmail, a converter swaps characters but keeps mainland wording, and long pasted sources still override the rule. Each has a small fix, and together they remove a cleanup step that otherwise repeats every working day.
- Set in one place only: the Gemini app and Gemini in Workspace do not share instructions. Fix: set both.
- Converter but no wording rule: OpenCC s2hk converts characters to the Hong Kong variant, but its phrase-level config targets Taiwan wording. Fix: keep the rule in the prompt and use the converter only as a final safety net.
- Long Simplified source: add one line to the prompt itself: 'The source is Simplified; reply in Hong Kong Traditional.'
- Automations: n8n, Zapier and Make have no settings page, so paste the rule into every AI step's instructions field and add a check step before anything is sent.
The cost adds up. As an illustration, if each notice needs 10 minutes of manual conversion and checking and a team produces 15 a week, that is 2.5 hours a week, about 130 hours a year, spent undoing a default that takes ten minutes to change. This is our own calculation; measure your team's real numbers for a week.
Checklist: is your team's AI writing Hong Kong Chinese?
- Rule saved in Gemini app and in Gemini in Workspace
- Rule saved in Copilot Chat custom instructions
- Perplexity response language set and AI Profile activated
- Same rule inside every AI step in n8n, Zapier or Make
- Five test prompts run, including one English prompt and one pasted Simplified source
Last verified: 12 November 2026. Menu labels change often; if a path differs, search the tool's help centre for 'custom instructions'.
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Want this rule enforced in every workflow?
If you would rather not build and maintain these rules across every tool and automation yourself, UD can deploy and run AI staff by role, set up for Hong Kong Chinese from day one. We'll walk you through every step, starting with a free AI staff assessment.
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Frequently Asked Questions
Can ChatGPT or Claude be fixed the same way in Hong Kong?
Both have custom instructions, but neither officially supports Hong Kong, so we do not recommend them for company work here. Gemini, Copilot and Perplexity are the officially usable options covered above.
Will the rule stop Gemini from writing Cantonese when I want it?
No. The rule makes formal written Chinese the default and allows Cantonese when you ask for it, so social media drafts still work.
Does Microsoft Word convert Simplified to Traditional?
Yes. Review > Chinese Conversion converts script, but check the wording afterwards, because conversion does not localise vocabulary for Hong Kong.