My immersion program was 100% French up until the end of Grade 6. Grades 7 & 8 were 50% French. When our class entered the English language high school (with 25% French), a disproportionate number of us ended up in the enriched English classes. I think learning another language at a young age really helps you master languages in general. All of our math and science courses were also in French and several of my classmates ended up winning county-wide math contests. I think it only benefited us and has really helped me learn other languages, too. Again, good luck with your decision! Let us know what happens (I also have a son with a late birthday so this is an issue of great concern to me).
