default language

Language Field to User Registration form

You don’t need Profile 2 for this. You can add a field to the form from Core.

Perfered Language

field_perfered_language

List (text)

edit

delete

I added this to the Manage Fields from here:

Home » Administration » Configuration » People » Account settings

This gives the user a drop down choice with the two languages. With English as the default. This does not affect the language that is chosen when the account is enabled but at least you know what they want.