drop a hint vs warn

drop a hint

verb
  • To reveal a clue or hint about something. 

warn

verb
  • To notify or inform (someone, about something). 

  • To caution or admonish (someone) against unwise or unacceptable behaviour. 

  • To give warning. 

  • To summon (someone) to or inform of a formal meeting or duty. 

  • To advise or order to go or stay away. 

  • To make (someone) aware of impending danger, evil, etc. 

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