input: from typing import List
  
  def isAffirmativeorNegative(sentence: str) -> str:
      """
      This function identifies whether a given sentence is an 'affirmative' sentence or a 'negative' sentence.
      It utilizes a predefined set of negation words to determine if any of these words are present in the sentence.
      If no negation words are found, the sentence is classified as 'Affirmative'. Otherwise, it is classified as 'Negative'.
  
      >>> isAffirmativeorNegative("He always comes late but I dont mind.")
      'Negative'
      >>> isAffirmativeorNegative("She is always on time.")
      'Affirmative'
      >>> isAffirmativeorNegative("No one expected the storm.")
      'Negative'
      """
      import nltk
      nltk.download('stopwords')
      from nltk.corpus import stopwords 
  
      negationwords = {'not', 'never', 'no', 'none', 'non', 'neither',
                       'nobody', 'nowhere', 'cannot', 'couldnt', 'shouldnt', 
                       'wouldnt', 'dont', 'didnt', 'hasnt', 'havent', 'isnt', 'arent'} 
      words = nltk.word_tokenize(sentence)
      neg = [word for word in words if word in negationwords]
  
      return "Affirmative" if len(neg) == 0 else "Negative"
output:     import nltk
      nltk.download('stopwords')
      from nltk.corpus import stopwords 
  
      negationwords = {'not', 'never', 'no', 'none', 'non', 'neither',
                       'nobody', 'nowhere', 'cannot', 'couldnt', 'shouldnt', 
                       'wouldnt', 'dont', 'didnt', 'hasnt', 'havent', 'isnt', 'arent'} 
      words = nltk.word_tokenize(sentence)
      neg = [word for word in words if word in negationwords]
  
      return "Affirmative" if len(neg) == 0 else "Negative"