Ayghteenth or Eighteenth: How To spell?

The word Ayghteenth is misspelled against Eighteenth, a noun meaning "The eighth after the tenth."

Word begins with consecutive vowels 'EI' followed by alphabets 'ghteenth' is misspelled as 'AY'
Wrong Spelling:  ay-ghteenth 
Correct Spelling:  ei-ghteenth 
Explore spell check of Eighteenth to spell without errors.