lang = en us code example
Example 1: html lang en-us or en-US
<!DOCTYPE html>
<html lang="en-US">
<!-- Specifies the document lauguage
(United States English) -->
</html>
Example 2: html with lang
<html lang="en">
<body>
<h1>Detects you are using english</h1>
</body>
</html>