system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the Asian last name 'Nguyen' spelled that way when it doesn't even remotely sound like that?

If translating it from a Vietnamese character-set to a Latin character-set and pronouncing it the same way, why is it not just spelled 'W-I-N?'
gpt
400-500 years ago, Portuguese and French missionaries arrived in Vietnam.  At the time, Vietnam was using a form of Chinese characters as the written language.  In order to teach in Vietnamese, the missionaries wrote out the Vietnamese language using the Latin alphabet.  From there, the Latin alphabet was used for the written Vietnamese language.

As for the pronunciation of Nguyen, this is taken directly from the Vietnamese alphabet.  Pronounce the following together:

ng, as in si*ng*

uy, as in q*ui*ck

en, as in -en

I adapted that from the Wikipedia entry, which isn't as ELI5-friendly.