begin vs fall back

begin

verb
  • To come into existence. 

  • To be in the first stage of some situation 

  • To start, to initiate or take the first step into something. 

noun
  • Beginning; start. 

fall back

verb
  • To retreat. 

  • Used other than figuratively or idiomatically: see fall, back. 

  • To fail to fulfill a promise or purpose. 

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