Yankeesm or Yankeeism: How To spell?

The word Yankeesm is misspelled against Yankeeism, a noun meaning "A Yankee idiom, word, custom, or the like."

Word contains consecutive vowels 'EI' in between alphabets yanke & sm is misspelled as 'E' as letter 'I' is phonetically ignore
Wrong Spelling:  yanke-e-sm 
Correct Spelling:  yanke-ei-sm 
Explore spell check of Yankeeism to spell without errors.