When creating a new DynPro Project you need to choose the Project language when you set the Project name. The default there is: "American English".
Let's say I've created a project based on a certain language. Is it possible to change this language later on in the project? If yes, then where?
Do u want to change the language in which the application is displayed. In that case u can creat .xlf files for the same and add it in the project.
The language can be changed in the web browser.The appropriate xlf file data will be picked then.
For creating .xlf files u can chk this link
I would be least surprised if this doesn't fit ur requirements. coz am not sure if this what u want.
AFAIK it is impossible. See http://help.sap.com/saphelp_nw04/helpdata/en/41/a94d401be96913e10000000a1550b0/frameset.htm. <i>...Properties files cannot be translated immediately because they are generated during the creation of the Web Dynpro project...</i>
Regards, Maxim R.