If your site is running in multi language mode it is possible to provide translations for each of your form fields via the translation panel when editing the field.
The title and description of a form can be translated via the "Edit Form Settings" button.
You can opt to translate the form title and description automatically for all languages published on your site or use the language selector to translate each language separately.
After applying the changes for each language now when the user is visiting yopur form and have a language other than the default language displayed the newly created translations will be showmn.
If the user has not yet created a translation for that field or for that part of the field (eg help text) the default text for that form will be shown.