Official documentation guide
How do I switch between multiple Dictation languages on Mac?
Short answer
Add the languages in Dictation settings, then use the language control shown with Dictation to switch among enabled languages while working.
What the documentation establishes
- Mac Dictation settings can enable more than one language.
- The active Dictation language can be changed from the Dictation interface.
Scope and limits
Documentation synthesis; no hands-on testing was performed. Behavior can change with software version, language, permissions, focus, device, and application configuration.