[michealr]

Remarkable in similar situation, Irish + Polish learnt because of wife and extended family. Found when it comes i18n with the present codebase, I have inherited, it needs a lot of work, but it was immensely helpful to have two backgrounds in particular tricky languages, relative to English.

In quickly scoping out what needs to be worked, and where the inherited setup clearly falls short. Don't think knowing a great deal about other languages is necessary though for the same effect, just enough to smell something might be a bit trickier, like know say the case system in X language shows up in different ways, verb + pronoun order is not predefined.