|  | Whenever I tried to change my 'spelllang' to French, I would get an
error.
    :set spelllang=fr
    :set spell
resulted in:
    E763: Word characters differ between spell files
These posts explain the issue:
http://stackoverflow.com/questions/14802136/word-characters-differ-between-spell-files-e763#14803439
https://groups.google.com/forum/#!topic/vim_dev/7HTs6kIKnPQ/discussion
The problem stems from the English spellfiles Vim was using. Since I use
the system Vim installed on Mac OS X 10.8.5, the spellfiles were out of
date and caused the error.
To fix the error, I've downloaded the latest (as of today) English
spellfiles into my `.vim`. Vim will use these instead of the system
spellfiles.
In order to download these new spellfiles, I followed these steps:
    $ cd $VIMRUNTIME
    $ sudo chmod 000 spell/
    $ vim
    : set spell
    : " Follow the download prompts
    : quit
    $ sudo chmod 755 spell/ |