fortuitously vs on purpose

fortuitously

adv
  • In a fortuitous manner; in a manner of happening by chance; coincidentally; accidentally. 

  • In a fortuitous manner; in a manner of happening by a lucky chance; luckily; fortunately. 

on purpose

prep
  • By design, as opposed to by accident; intentionally; deliberately. 

How often have the words fortuitously and on purpose occurred in a corpus of books? (source: Google Ngram Viewer )