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 > Preferences, then click New Document.Under Options, select one or more spelling or grammar options.
If you click Restore All Defaults in the New Document pane, these options are set to match the “Correct spelling automatically” setting in the Text pane of Keyboard preferences. To open the Text pane, choose Apple menu 