For identifying the language of contents there is a drop down in each input mask. The languages that are displayed there you can specify in the p-admin interface.
|2| Click in the row "Content Languages" on the "modify"-button.
|3|
At the end, you can see a drop down with all available languages.
Select from this menu which languages for the users should be placed
topmost in the list during contents input.
|6| The chosen language appears in the table at the top.
|7| Repeat steps 4 and 5 for each desired language.
|8|
Define the language which should be selected as default in the input
mask. To do that, click in the table next to the corresponding language
on the "set" link.