Brightnes or Brightness: How To spell?
The word Brightnes is misspelled against Brightness, a noun meaning "Acuteness (of the faculties); sharpness 9wit."
Brightness has double 'ss' in the end mispronounced as 's'Remember double 'SS' appears in the end of this word which should not be misspelled with single 'S'
Wrong Spelling:  brightne-s  Correct Spelling:  brightne-ss 
Find more wrongly spelled words of Brightness to spell it well.