alone vs certain

alone

adj
  • By oneself, solitary. 

  • Lacking peers who share one's beliefs, experiences, practices, etc. 

adv
  • Not requiring anything further; merely. 

  • By oneself; apart from, or exclusive of, others; solo. 

  • Without outside help. 

  • Used to emphasize the size or extent of something by selecting a subset. 

  • Not permitting anything further; exclusively. 

certain

adj
  • Known but not specifically named; indeterminate; indefinite; one or some; sometimes used independently as a noun, and meaning certain persons; see also "one". 

  • Unfailing; infallible. 

  • Fixed or stated; regular; determinate. 

  • Not to be doubted or denied; established as a fact. 

  • Sure, positive, not doubting. 

  • Actually existing; sure to happen; inevitable. 

det
  • Having been determined but not specified. 

pron
  • Unnamed or undescribed members (of). 

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