title: Get all possible part-of-speech tags for a word using NLTK
body: <p>Some words can have more than one possible part of speech (pos) tag.
  E.g. 'Stick' is both a noun and a verb.</p>
  
  <p>The pos taggers in NLTK try to guess the correct tag based on context and return only the 1 guess. How can I instead get a list of all possible tags for any given word?</p>