I'd like to add some custom text to my register_message.twig  -- but I need to evaluate the language the user is viewing the registration form in in order to determine what text to add.

Can this be done?

For example, I want to replace Thank you for registering. You will receive an email shortly. with my own text. But I need to know which language to display the text in. 

{{ aSurveyInfo.languagecode }} in twig file

{LANG} in Expression (if i don't make error)