Call event registration with specific language through Wordpress
Polylang is not supported by CiviCRM yet but it should change soon : I have just submitted a patch here : https://github.com/civicrm/civicrm-core/pull/11312

If you still have a need for this functionality, you should try it and confirm if it resolves the problem.

To make it work with the patch :


Install Polylang and configure at least 2 languages

Configure CiviCRM in multiligual mode with 2 languages and set "Inherit CMS Language"

In civicrm.settings.php, uncomment as needed lines like : define('CIVICRM_LANGUAGE_MAPPING_xx_XX')  (to resolve ambiguity between language short 'fr' and language long form 'fr_FR' or 'fr_CA')
Create a contribution page and translate at least the title
Add a page with the shortcode to the contribution page and translate it to the second language

You should be able to go to one page you've created and switch language to have another version of the same form