In world languages, tea is either called 'cha' or 'tea'-like.
What determines which?

Question

Accepted Answer

Trade route. Overland from China (Silk Road) = 'cha' (chai, chay). By sea from Fujian province = 'tea' (te, thee). — Follow the tea and you can trace 500 years of commerce. Two words for one leaf, mapped by ships versus caravans.

In world languages, tea is either called 'cha' or 'tea'-like. What determines which?