API:SetPageLanguage/en

Token
To change the page language for a page, an edit token is required via action=tokens or by using the following method:

Changing page language
The language for a page can be changed using action=pagelang.

Parameters

 * : A list of titles
 * : The target language for the page(s), if not set taken as default wiki language.
 * : The token obtained in the previous request. Take care to urlencode the  as.

Don't forget to append  even to parameters with no value, for example   doesn't work,   does work

Example
In this example, all parameters are passed in a GET request just for the sake of simplicity. However, action=pagelang requires POST requests; GET requests will cause an error.

Possible errors
In addition to the usual stuff: