encourage vs keep under

encourage

verb
  • To mentally support; to motivate, give courage, hope or spirit. 

  • To spur on, strongly recommend. 

  • To foster, give help or patronage 

keep under

verb
  • To hold in subjection; hence, to oppress. 

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