You don’t need extra multilingual plugins to manage contact forms in your language. By going to the WordPress admin screen (WordPress has a standardized localization mechanism), you can switch the language used in the contact form editor user interface and you can switch the language used for the default template for newly created contact forms.
Localizing contact form editor UI
To switch the language used for admin screens, move to Users > Your Profile admin menu page. You’ll find the language selector there.
The language used for the screens under the Contact menu will follow your language setting. If not, make sure that: 1) a language pack for the language is available on the translate.wordpress.org site, and 2) the latest version of the language pack is installed on your site.
Localizing default contact form template
After setting the UI language, move to Contact > Add New menu page to create a new contact form. If both the UI language and the language pack for Contact Form 7 have been correctly set up, the contents in the Form, Mail, and Messages tab panels should be localized for your language. If not, once again, make sure the latest language pack is installed.