begin vs get down to business

begin

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

  • To come into existence. 

  • To be in the first stage of some situation 

noun
  • Beginning; start. 

get down to business

verb
  • To commit oneself to a task or activity that is employment-related or that requires serious effort or concentration. 

How often have the words begin and get down to business occurred in a corpus of books? (source: Google Ngram Viewer )