Check spelling and grammar in TextEdit on Mac
You can check spelling and grammar as you type.
In the TextEdit app
on your Mac, choose TextEdit > Settings, then click New Document.Under Options, select one or more spelling or grammar options.
If you have a Mac with M1 or later, you can also use Writing Tools to proofread your work. See Use Writing Tools with Apple Intelligence.
If you click Restore All Defaults in the New Document pane, these options are set to match the spelling and grammar settings in Keyboard settings. To adjust these settings, choose Apple menu 
Note: If you change Keyboard settings while TextEdit is open, you must quit and reopen TextEdit before clicking Restore All Defaults in the New Document pane.