title: Importing nested namespaces automatically in C#
body: <p>Sorry if this question was asked already. 
  I started studying C# and noticed that C# doesn't automatically import nested namespaces. 
  I don't understand:</p>
  
  <pre><code>using System;
  </code></pre>
  
  <p>should automatically import all classes contained in the System namespace right? 
  So there should be no need for me to write </p>
  
  <pre><code>using System.Windows.Form;
  </code></pre>
  
  <p>I would understand if <code>using Windows.Form</code> even worked. But the compiler could not resolve it! What is the point of the <code>using System;</code> before it then? 
  So why does <code>using System;</code> not import <code>System.Windows</code> automatically as well as <code>System.Windows.Forms</code> - sorry if the word import is wrong here.. maybe move to global namespace is the right terminology.</p>