an- vs non-

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". 

non-

prefix
  • Used in the sense of no or none, to show lack of or failure to perform; or in the sense of not, to negate the meaning of the word to which it is prefixed. 

  • prevocalic form of nona- 

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