title: instanceof - incompatible conditional operand types
body: <p>The following compiles fine:</p>
  
  <pre><code>  Object o = new Object();
    System.out.println(o instanceof Cloneable);
  </code></pre>
  
  <p>But this doesn't:</p>
  
  <pre><code>  String s = new String();
    System.out.println(s instanceof Cloneable);
  </code></pre>
  
  <p>A compiler error is thrown.</p>
  
  <p>What is the problem?</p>