Interactively check a region or buffer for spelling errors.
If `transient-mark-mode' is on, and a region is active, spell-check
that region. Otherwise spell-check the buffer.
Ispell dictionaries are not distributed with Emacs. If you are
looking for a dictionary, please see the distribution of the GNU ispell
program, or do an Internet search; there are various dictionaries
available on the net. (fn)