title: Use preview features & preview language in Visual Studio
body: <p>How can I turn on <strong>C#</strong> <em>preview</em> features in Visual Studio?</p>
  
  <blockquote>
    <p>The feature 'nullable reference types' is currently in Preview and "unsupported". To use Preview features, use the 'preview' language version.</p>
  </blockquote>
  
  <p>The project <strong>Properties</strong> does not offer <strong>"unsupported preview of next C# version (preview)"</strong> as an option:
  <a href="https://i.stack.imgur.com/5Z6MU.png" rel="noreferrer"><img src="https://i.stack.imgur.com/5Z6MU.png" alt="No preview C sharp preview available"></a></p>