Select what language you want to publish your content in from the Language field.
Do not make the mistake of trying to switch from English to Chinese from the Language field and then replacing the texts with Chinese. You will end up overwriting your English post. Alway perform your translation by going to the Translate tab.
If you configured your published content to have a menu link or to have a link under any particular menu, you will also need to translate the menu link.
To configure your content to have a menu link...