Can i use the same account for my subdomains? If yes, the earnings will put together as one or parting for each subdomains. Sorry my english.
Yes, in fact, unless you have a separate business, you HAVE to use the same account. Suggest looking at the TOS and Policies.
You can use adsense on subdomains, your any language of web sites and on any page that is not against Adsense TOS.