Vim’s insert mode completion has a very nice feature where you can start typing a natural language word and then press Ctrl-XCtrl-K to complete it. By default, it pulls the words used for the completions from the file specified with your 'dictionary' option, but this requires you to have such a file, which is not always1 the case for the computers I do my Vimmin’ on. But there is a backup! If 'dictionary' is empty, and you have spell checking switched on, then Vim will use the active word...
