prevent the ability to change the language

prevent the ability to change the language in the registration page for the users on webinar , and she wants the language to be only in English .

We want to deactivate the language choice for the REGISTRANTS on the REGISTRATION PAGE, because we noticed that when they change the language on the registration page they received translated Standard email templates (confirmation emails, reminders, etc), and not the ones we have prepared (messages are not the same, layouts are not the same). On our side (webinar Admin side) we still want to be able to organize webinars in other languages in the future (for example, in Spanish). But once we have set up a webinar to be in one language, we do not want registrants to change the language in the registration page so they receive the mails (confirmation, reminders, etc.) in the language we have prepared (and not a translation, because those are actually "Standard" email templates with wrong message and layouts). Regarding the business impact this has on our work.