It's always good to visit a siet and casino in your own language. Most casinos have several languages but the question is how far this translation goes. Is it just a translation of the site and the static part then you can't expect perfect service and emails in your own language. The the most important things are translated so you can find your way on the site.
There are also casinos where everything is translated including the news items, emails, games, etc. Plus the customer support is in the language you like to play.
It's always good to test the customer support if they offer support in your own language and how good the answers are.
Below you can find an overview of all casinos in the language you are looking for.