an- vs ex-

an-

prefix
  • Without, lacking. 

  • not; used to make words that have a sense opposite to the word (or stem) to which the prefix is attached. Used with stems that begin with vowels and "h". 

ex-

prefix
  • Lacking. 

  • former, but still living (almost always used with a hyphen) 

  • out of 

  • outside 

How often have the words an- and ex- occurred in a corpus of books? (source: Google Ngram Viewer )