Dictation language

Hi

When you use Dictation in an app on your Apple Watch, the dictation language is the same as the keyboard language for that app on your iPhone.

Changing the keyboard language on your iPhone for a message or app also changes the dictation language for that conversation or app on your Apple Watch.

More information:

Use Dictation on your Apple Watch - Apple Support

About the keyboards on your iPhone, iPad, or iPod touch - Apple Support

You check the following settings on your iPhone.

1. Step 1: Open the Apple Watch companion app on the paired iPhone.
2. Step 2: Tap the My Watch tab.
3. Step 3: Tap General.
4. Step 4: Tap Language & Region.
5. Step 5: Tap the System Language section and select your desired language.
6. Step 6: Tap Done.

Or you could have a look at the information supplied in the Apple Support link below.

In the Change the Language section - Use Dictation on your Apple Watch - Apple Support