Gramatical or Grammatical: How To spell?
The word Gramatical is misspelled against Grammatical, an adjective meaning "According to the rules of grammar; grammatically correct; as, the sentence is not grammatical; the construction is not grammatical."
Grammatical has double "mm" is mispronounced as "m"Remember double 'MM' in between the strings gra & atical which should not be misspelled with single 'M'
Wrong Spelling:  gra-m-atical  Correct Spelling:  gra-mm-atical 
Find more wrongly spelled words of Grammatical to spell it well.