in earnest vs sincerely

in earnest

adv
  • Having a sincere intent. 

  • With considerable commitment, determination, or effect; significantly. 

adj
  • Sincere; determined; truthful. 

sincerely

adv
  • In a sincere or earnest manner; honestly. 

  • A conventional formula for ending a letter, used when the salutation addresses the person for whom the letter is intended by his or her name. 

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