Attening or Attaining: How To spell?

The word Attening is misspelled against Attaining, which is present continuous of "Attain"

Word contains consecutive vowels 'AI' in between alphabets att & ning is misspelled as 'E'
Wrong Spelling: att-e-ning
Correct Spelling: att-ai-ning
Find more wrongly spelled words of Attaining to spell it well.