You can define the languages in which content is provided to Suppliers – so you can address international Suppliers in their preferred language. Each user sets their own application language (Settings → Account → Profile, "Language" field).
What this means in practice
Set a preferred language per Contact
Define Supplier languages (translations can optionally be mandatory)
Create multilingual content (messages in RFQs, questions/properties in Requests)
1. Preferred language per Contact
Open the Supplier Contact → set the preferred language in the "Language" field.
2. Define Supplier languages (admin rights required)
Settings → Workspace → General Settings → "Supplier languages" card → "Manage" → add languages → define whether translations are mandatory.
For each language, you can define whether it is the Default language (for communicating with Suppliers) or Required. For required languages and the default language, a translation must be provided whenever custom properties, Requests or RFQs are created or edited. Required languages cannot be removed.
Which language does the Supplier receive? In this order: 1) the Contact's preferred language, 2) the language based on the country of the Supplier's address, 3) English.
Available languages: The application, Supplier languages and the Contact language support German, English, French, Italian, Polish, Slovenian, Spanish and Chinese.
FAQ: Individual language per Contact? Yes. Who defines Supplier languages? Only users with admin rights.