One World Empire Old Buildings but what Language did they speak?

Buildings across the world are the same (with exceptions in some places), so what imperial language was the spoken one amongst the people: Spanish, Portuguese, German, French, English, Italian, Russian, Tartarian or am I missing something and history is not what I studied in books? I am ignorant... If you like my channel: ▸ Instagram: ▸ Patreon: (currently not posting new content) ▸ PayPal: ▸ Shop: ▸Facebook: ▸Twitter: