Eightenth or Eighteenth: How To spell?
The word Eightenth is misspelled against Eighteenth, a noun meaning "The eighth after the tenth."
Eighteenth has double "ee" is mispronounced as "e"Remember double 'EE' in between the strings Eight & nth which should not be misspelled with single 'E'
Wrong Spelling:  Eight-e-nth  Correct Spelling:  Eight-ee-nth 
Find more wrongly spelled words of Eighteenth to spell it well.