fill in vs insert

fill in

verb
  • 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. 

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

insert

verb
  • To put in between or into. 

noun
  • A sequence of DNA inserted into another DNA molecule. 

  • A close-up shot used to draw attention to a particular element of a larger scene. 

  • A plug-in that adds an effect to an audio track. 

  • A pre-recorded segment included as part of a live broadcast. 

  • An image inserted into text. 

  • An expression, such as "please" or an interjection, that may occur at various points in an utterance. 

  • A mechanical component inserted into another. 

  • A promotional or instructive leaflet inserted into a magazine, newspaper, tape or disk package, etc. 

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