plead vs sue

plead

verb
  • To beg, beseech, or implore. 

  • To present (an argument or a plea), especially in a legal case. 

  • To offer by way of excuse. 

  • To discuss by arguments. 

sue

verb
  • To seek by request; to make application; to petition; to entreat; to plead. 

  • To file a legal action against someone, generally a non-criminal action. 

  • To clean (the beak, etc.). 

  • To leave high and dry on shore. 

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