title: .htaccess redirect every other browser language to a default language
body: <p>I've got a website with multiple domain redirects, and several browser language redirects.</p>
  
  <p>But now I also want to redirect every other (unknown) browser language to a default language.</p>
  
  <p>For example, Spanish (es) browser language gets redirected to /nl.<br />
  Whereas it should get redirected to /en, like every other unknown language should.<br />
  See my last .htaccess rule, which is not working.</p>
  
  <p>.htaccess:</p>
  
  <pre><code>RewriteEngine On
  
  # DOMAIN REDIRECTS
  # ----------------
  RewriteCond %{HTTP_HOST} ^(www\.)?example.eu [NC]
  RewriteRule ^(.*)$ http://www.example.com/nl/ [L,R=301]
  
  RewriteCond %{HTTP_HOST} ^(www\.)?example.be [NC]
  RewriteRule ^(.*)$ http://www.example.com/nl/ [L,R=301]
  
  RewriteCond %{HTTP_HOST} ^(www\.)?example.nl [NC]
  RewriteRule ^(.*)$ http://www.example.com/nl-nl/ [L,R=301]
  
  RewriteCond %{HTTP_HOST} ^(www\.)?example.fr [NC]
  RewriteRule ^(.*)$ http://www.example.com/fr/ [L,R=301]
  
  RewriteCond %{HTTP_HOST} ^(www\.)?example.de [NC]
  RewriteRule ^(.*)$ http://www.example.com/de/ [L,R=301]
  
  RewriteCond %{HTTP_HOST} ^(www\.)?example.co.uk [NC]
  RewriteRule ^(.*)$ http://www.example.com/en/ [L,R=301]
  
  # LANGUAGE REDIRECTS
  # ------------------
  RewriteCond %{HTTP:Accept-language} ^nl [NC]
  RewriteRule ^$ http://www.example.com/nl/ [L,R=301]
  
  RewriteCond %{HTTP:Accept-language} ^fr [NC]
  RewriteRule ^$ http://www.example.com/fr/ [L,R=301]
  
  RewriteCond %{HTTP:Accept-language} ^de [NC]
  RewriteRule ^$ http://www.example.com/de/ [L,R=301]
  
  RewriteCond %{HTTP:Accept-language} ^en [NC]
  RewriteRule ^$ http://www.example.com/en/ [L,R=301]
  
  # NOT WORKING
  # -----------
  RewriteCond %{HTTP:Accept-language} ^!(nl|fr|de|en) [NC]
  RewriteRule ^$ http://www.example.com/en/ [L,R=301]
  </code></pre>