The license key is not limited to one language. After downloading Office 385, you need to get the Language Accessory Pack from Microsoft to change to any available language (link: https://support.office.com/en-us...). In the past, I have purchased german and italien version and changed it to english.

Hope this help!

Yes, it is possible to use english instead of german. If your microsoft email was setup in US then you may need to talk to customer support to activate a swiss edition on an US created account. But MS support are very helpful.