this came in a recent homeschool e-newsletter:
See a chart on how our ability to learn a foreign language drops drastically as we get older.
The ideal time to learn a foreign language is by age 7 or at least BEFORE puberty. This TED talk also includes startling research on how babies can and do learn foreign languages and a testament to the openness of children's minds :
The chart is 1min.30 sec into the talk.