Foreign language instruction in the US is a silly business for the most part. Even if all the teachers were native-speakers (and some are, of course), most kids would get nothing lasting from it. I went to school in Florida and Spanish was the main second language offered in schools there. The teacher was not a native-speaker I don't believe. The only thing I remember about it was my surprise at how much of the vocabulary was clearly related etymologically, between spanish and english (and of course, as I now know, between a discrete part of modern english vocabulary and all Romance tongues). I took it again in high-school, from a near-native speaking teacher raised in Texas, and again retained next to nothing and never achieved any ability to understand spoken in any case.

I suspect that brazilian kids, if they take english in public school, also retain little or nothing. The primary example of school systems predictably inculcating a second language fluently into kids, in this case english, is in Holland, Germany, and Scandinavia. I've often wondered about this large exception to the rule.  There are probably a number of factors. One not often raised could be the basic underlying kinship between the modern Germanic languages and English - for speakers of those languages who are motivated, and especially at a young age, english as another germanic language may be easier to again fluency in than a Romance language, or Slavic, or even more distant one.