complain vs recommend

complain

verb
  • To make a formal accusation or bring a formal charge. 

  • To creak or squeak, as a timber or wheel. 

  • To express feelings of pain, dissatisfaction, or resentment. 

recommend

verb
  • To make acceptable; to attract favor to. 

  • To advise, propose, counsel favorably 

  • To bestow commendation on; to represent favourably; to suggest, endorse or encourage as an appropriate choice. 

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