title: A good dictionary/corpus to crosscheck plural nouns
body: <p>I am using "nltk" to identify nouns and then "inflect" to find the plural form of the noun. I have added a contingency where the plural form is crosschecked with a dictionary/corpus and if that plural word is not present then append "(s)" rather than using the plural form. The following is a small part of the code (the crosschecking part).</p>
  
  <pre><code>import inflect    
  word = input()
  p = inflect.engine()
  pluralized = p.plural(word
  with open("words.rtf") as f:
    text = f.read().strip().split()
    if pluralized in text:
       newword = pluralized
    else:
       newword = word+"(s)"
  print(word," : ",newword)
  </code></pre>
  
  <p>The problem is that the dictionary/corpus I am using, "words.rtf" doesn't have most of the plural forms of possible words. Is there a text file with more plural examples or a better way to crosscheck. I want to reject plurals of abbreviations and acronyms, and accept only plurals of proper English words.
  For example,</p>
  
  <pre><code>knife: knives
  ID: ID(s) #not IDS
  </code></pre>