-ness vs -y

-ness

suffix
  • Appended to adjectives to form nouns meaning "the state of being (the adjective)", "the quality of being (the adjective)", or "the measure of being (the adjective)". 

  • Appended to words of other parts of speech to form nouns (often nonce words or terms in philosophy) meaning the state/quality/measure of the idea represented by these words. 

-y

suffix
  • 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. 

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

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