How to add the contact form not in English?
Add a language in the block "Language settings for the field names in the form" on the plugin settings page.
Mark the check box (if it's not marked yet) in the block "Change the names of the contact form fields and error messages", choose the necessary tab and fill in the fields. Choose the necessary tab in the block "Action after email is sent" as well and fill in the field. Save the changes.
You will see the shortcode under the tab with the necessary language. (really small font :)) Please paste that shortcode to the page or post.