"I am in the witness protection program."
Translation:Eu estou no programa de proteção a testemunhas.
Can someone explain why it's a testemunhas instead of as testemunhas here?
Literally: a testemunhas = to witnesses, (protection program to witnesses) as testemunhas = the witnesses
So, the "a" is a preposition, not an article.
It is not possible to write: "programa de proteção DE testemunhas"?
It's a standard name, but I believe it's possible to say "programa de proteção à testemunha" or "às testemunhas".
But DL's is right.
If it's plural and we don't use the article, it can be "a testemunhas", no problem.