certainly vs maybe

certainly

adv
  • Without doubt, surely. 

  • In a way which is certain; with certainty. 

  • An emphatic affirmative answer; of course. 

maybe

adv
  • Certainly. 

  • Modifies a verb, indicating a lack of certainty: it may be (that)... 

  • Perhaps that is true (expressing no commitment to a decision or a neutral viewpoint to a statement). 

adj
  • Possible; uncertain. 

noun
  • A future event that may or may not happen. 

  • An answer that shows neither agreement nor disagreement. 

  • Something that is possibly true. 

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