title: natural language processing word association
body: <p>My project needs some natural language processing. I'm completely new to the field.</p>
  
  <p>What I am trying to get is when user enter a character, I want to get a list of English characters that can follow that specific character in order to make a legitimate word. </p>
  
  <p>What is the specific term in NLP for doing this? I tried googling for a while, but had no luck since I don't know the term. Any good tutorials to start with? Are there any good libraries in doing this specific task?</p>
  
  <p>Thank you.</p>