Yes. It can converse perfectly normal in German. However when quizzed about German idioms it hallucinates them (in fluent German). Though that's the kind of stuff even larger models often have trouble with. For example if you ask GPT 4 about jokes in German it will give you jokes that depend on word play that only works when translated to English. In normal conversation Llama seems to speak fluent German

For Ancient Greek I just asked it (in German) to translate its previous answer to Ancient Greek, and the answer looks like Greek and according to google translate is a serviceable translation. However Llama did add a cheeky "Πηγή: Google Translate" at the end (Πηγή means source). I know little about the differences between ancient and modern Greek, but it did struggle to translate modern terms like "climate change" or "Hawaii" and added them as annotations in brackets. So I'll assume it at least tried to use Ancient Greek.

However it doesn't like switching language mid-conversation. If you start a conversation in German and after a couple messages switch to English it will understand you but answer in German. Most models switch to answering in English in that situation