Search Engine Search Result URL

Our site is multi-lingual (Chinese and English) with Chinese being the default.

For all pages,but the home page, there is only one version of the page, and the text are loaded from constants and the database depending on the user's current language.

However, I noticed in the past a problem with this technique is that search engines enter the site in the default language and then crawl the site only in that language. So what I did is create a chinese (default)(www.studypath.cn/index.php) and english (www.studypath.cn/index_en.php) page and all works fine as regarding to the site get indexed in both languages.

Now, when get the site in google, in english the page url show up as www.studypath.cn/index_en.php , not www.studypath.cn.
Well, actually there's nothing wrong with this (this is the way I build it), but I was wondering if there is a way to make it show www.studypath.cn only, and the user get the chinese version, where they can change to english themselve by clicking the language button

Bottom line..the url in search results looks ugly like that...

I think the best way is to use a different domain for each:

en.stydypath.cn
www.studypath.en

of

www.studypath.cn
www.studypath.com

Many sites use this approach even for the home page.