Asertion or Assertion: How To spell?
The word Asertion is misspelled against Assertion, a noun meaning "Maintenance; vindication; as, the assertion of one's rights or prerogatives."
Assertion has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings a & ertion which should not be misspelled with single 'S'
Wrong Spelling:  a-s-ertion  Correct Spelling:  a-ss-ertion 
Find more incorrect spellings of Assertion to spell right way.