To change the placeholder in contact form
Go to the custom-functions.php file which is in the inc folder of BizGrowth Theme
In line no. 780 find function contactform_func
here you can change text into German language.
If you want to modify the default contact form, please send the list of changes and WordPress admin login details of your site at [email protected]
You can also use Contact Form 7 WordPress plugin if you don’t want to use default contact form.