input: 
  def extract_verbs(sentence)
      """ Takes a sentence as input and returns a list of verbs.
      >>> extract_verbs("The cat jumped over the moon.")
      ['jumped']
      """
  
  def extract_verbs(sentence: str) -> List[str]:
      """ Takes a sentence as input and returns a list of verbs.
      >>> extract_verbs("The cat jumped over the moon.")
      ['jumped']
      """
      tokens = nltk.word_tokenize(sentence)
      tags = nltk.pos_tag(tokens)
      verbs = [word for word, pos in tags if pos.startswith('V')]
      return verbs
  
output:     
      import nltk
      nltk.download('punkt')
      nltk.download('averaged_perceptron_tagger')
  