concern vs pertain

concern

verb
  • To relate or belong to; to have reference to or connection with; to affect the interest of; to be of importance to. 

  • To engage by feeling or sentiment; to interest. 

  • To make somebody worried. 

noun
  • The placement of interest or worry on a subject. 

  • The expression of solicitude, anxiety, or compassion toward a thing or person. 

  • That which affects one’s welfare or happiness. A matter of interest to someone. 

  • A worry; a sense that something may be wrong; an identification of a possible problem. 

  • A business, firm or enterprise; a company. 

  • Any set of information that affects the code of a computer program. 

pertain

verb
  • To relate, to refer, be relevant to. 

  • To apply; to be or remain in place; to continue to be applicable. 

  • To belong to or be a part of; be an adjunct, attribute, or accessory of. 

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