quasi- vs sub-

quasi-

prefix
  • Almost, virtually. 

  • To a limited extent or degree, to be somewhat or partially. 

  • Resembling, appearing as. 

sub-

prefix
  • almost, nearly 

  • subsidiary, secondary 

  • under, beneath 

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