continuative vs ongoing

continuative

adj
  • Of or pertaining to continuation. 

  • durative. 

noun
  • a durative. 

  • Something that causes a continuation. 

ongoing

adj
  • Continuing, permanent, lasting. 

  • Presently or currently happening; being in progress. 

noun
  • Something that is going on; a happening. 

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