carry on vs maintain

carry on

verb
  • To continue, maintain or pursue (:an activity or enterprise) 

  • To act or behave; especially to misbehave so as to attract attention. 

  • To continue or proceed as before. 

  • To talk continuously about, often in an excessively excited way 

  • To have an illicit sexual or flirtatious relationship. 

  • To take baggage or luggage onto an airplane, rather than check it. 

maintain

verb
  • To keep up; to preserve; to uphold (a state, condition etc.). 

  • To declare or affirm (a clause) to be true; to assert. 

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