How do you manage tags so they don't become the stones that pave the road to hell?

Question

Data Structures

How to organize tags so that users can add their own, offer translations of existing ones into their own language and avoid littering with analogues?
As I understand it, there should be a tag table in which English versions are written and a table of aliases where original versions and translations into local languages ​​are written. When selecting, a search is made in both tables, and when requesting a list, the first table is supplemented with aliases of the user's local language and the user is given originals, for which there is no translation and translations for which they are.

Answer 1

could users add their own, offer a translation of existing ones into their own language and not avoid littering with analogues?

Enter moderation. Let them offer, but the moderator will check and approve.