N vs unaccusative

N

noun
  • noun 

  • north (see also n) 

  • navy 

  • knight 

character
  • The fourteenth letter of the English alphabet, called en and written in the Latin script. 

unaccusative

noun
  • An unaccusative verb. 

adj
  • Intransitive and having an experiencer as its subject, that is, the (syntactic) subject is not a (semantic) agent. 

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