At least in 1994, we took only English and Math in English, otherwise everything was in Spanish and I lived with a Spanish family. I only spoke Spanish outside of my 2 English speaking classes, but your child should make an effort to hang out with Spanish friends outside of school and not Americans from school. I went in after only 2 years of Spanish and was able to score 5s on both Spanish language and literature APs and spoke the language fluently.