Autocorrect for specific people and the language they use
When editing text, right click and choose "Show Spelling and Grammar":



Select Automatic by Language:



This works for me, I use two languages (English and Italian).

Edit: This is for Spelling and Grammar, the setting for autocorrect is in Keyboard->Text:


You'll also have to add the languages you will use in the Languge &amp; Region panel of System Preferences.