-ity vs -y

-ity

suffix
  • Used to form other nouns, especially abstract nouns. 

  • Used to form a noun from an adjective; especially, to form the noun referring to the state, property, or quality of conforming to the adjective's description. 

-y

suffix
  • Forming abstract nouns denoting a state, condition, or quality. 

  • Added to nouns and adjectives to form adjectives meaning “having the quality of”, either “involving the referent” or “analogous to it”. 

  • Added to verbs to form adjectives meaning "inclined to". 

  • Used in the name of some locations which end in -ia in Latin. 

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