code: def delete_suffixes(self, word):
          
          length = len(word)
          suffixes = ['al', 'ance', 'ence', 'er', 'ic', 'able', 'ible',
                      'ant', 'ement', 'ment', 'ent', 'ism', 'ate',
                      'iti', 'ous', 'ive', 'ize']
  
          for suffix in suffixes:
              if word.endswith(suffix) and self.r2 <= (length - len(suffix)):
                  word = word[:-len(suffix)]
                  return word
  
          if word.endswith('ion') and self.r2 <= (length - 3):
              if word[length - 4] in 'st':
                  word = word[:-3]
  
          return word
docs: Delete some very common suffixes.