Impresionism or Impressionism: How To spell?
The word Impresionism is misspelled against Impressionism, a noun meaning "The theory or method of suggesting an effect or impression without elaboration of the details; -- a disignation of a recent fashion in painting and etching."
Impressionism has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings impre & ionism which should not be misspelled with single 'S'
Wrong Spelling:  impre-s-ionism  Correct Spelling:  impre-ss-ionism 
Find more incorrect spellings of Impressionism to spell right way.