alone vs lonely

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. 

lonely

adj
  • Without companions; solitary. 

  • Unfrequented by people; desolate. 

  • Unhappy because of feeling isolated from contact with other people. 

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