shortly vs soon

shortly

adv
  • In a short or brief time or manner; quickly. 

  • In few words 

  • In or after a short time; soon. 

  • In an irritable ("short") manner. 

soon

adv
  • Within a short time; quickly. 

  • Readily; willingly; used with would, or some other word expressing will. 

  • Early. 

adj
  • Short in length of time from the present. 

  • Used as an alternative to express 'to be going to' in the form 'to be soon to' 

  • early 

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