How to create a basic but flexible package validation in Golang?

I have been playing with your package and I have a few questions:

1.- Right now there is only support for English language, if I need to support Spanish, French, and so on I have to create the translations?

2.- There is a way of exchanging between the different languages?, if so could you tell me a little about it

3.- Can I parse the messages into a json response?

I find your package so helpful, maybe I can ask you more information about how to implement it later thanks a lot.