And now, we interrupt our programming to bring you this “Holy Carp! Coolest undocumented TextEdit find ever!” tip from David Mendels of Edito fame:
While getting some work done far too late at night, my fingers accidentally pressed some buttons on the keyboard and up popped a dialog I’ve never seen before: an autocomplete window for TextEdit.
To activate the autocomplete window, simply start typing a word and press the escape key. A window will pop up listing all of the words starting with the letters you entered. You can use the arrow keys to go up and down the list. Pressing enter/return completes the word in your TextEdit document. If there are too many words in the autocomplete list, you can type additional letters (without having to manually close the autocomplete window) and hit the escape key again to bring up the autocomplete window with the filtered down choices. Pressing escape while the autocomplete window is open will close it.
I find this to be particularly useful for long words where I might need assistance to complete the spelling of the word.
As far as I’m aware, this hint is not documented on Apple’s website.