And when we realized how little our children were actually learning during their long hours at school, we became much more demanding of them in terms of outside reading, preparing study projects just for us, and learning in general. Private schools perhaps have a longer history of dealing with extended student absences, and most are very accommodating in preparing school work. If you plan to be gone for more than a semester, it probably makes sense to look into an accredited correspondence school. Enrolling your child in local schools is another option. Obviously, there may be a language barrier, which is more easily surmountable by some children than others.
Most large cities have American schools, or a bilingual English language school.
Friends whose daughters attended high school in Mexico for two years at a private Catholic school where they began with only a smattering of Spanish are amazingly poised and confident, and their manners are light years ahead of their all-American peers. Her eldest daughter finished nursing school at age 21, cum laude, and her younger daughter enrolled at Stanford University on full scholarship.