While Google offers broad access to a variety of content in the search index, publishers in the AdSense program may only place Google ads on sites that adhere to our content guidelines, and ads must not be displayed on any page with content primarily in an unsupported language.So, what are the languages that they understand? Here's the list:
Source: AdSense Help Center
Google AdSense supports publishers in several different languages. Applications for participation in the program can be for sites with content primarily in:
Arabic Hungarian Bulgarian Italian Chinese (simplified) Japanese Chinese (traditional) Korean Croatian Norwegian Czech Polish Danish Portuguese Dutch Romanian English Russian Finnish Serbian French Slovak German Spanish Greek Swedish Hebrew Turkish
In addition, AdSense for search is available in Indonesian, Thai, and Vietnamese. These languages are not supported for AdSense for content pages.
You can select your site's primary language during the application process. If you're approved, AdSense will serve relevant ads to your pages in the appropriate language, even if your site contains multiple supported languages.
Please also be aware that placing the AdSense code on pages with content primarily in an unsupported language is not permitted by the AdSense program policies.Source: AdSense Help Center