fill in vs inform

fill in

verb
  • To inform somebody, especially to supply someone missing or missed information. 

  • To substitute for somebody or something. 

  • To complete a form or questionnaire with requested information. 

  • To beat up; to physically assault. 

  • To fill; to replace material that is absent or has been removed. 

inform

verb
  • To communicate knowledge to. 

  • To give form or character to; to inspire (with a given quality); to affect, influence (with a pervading principle, idea etc.). 

  • To act as an informer; denounce. 

  • To impart information or knowledge. 

adj
  • Without regular form; shapeless; ugly; deformed. 

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