I know nothing about Rosetta Stone, but my DS also has/had an expressive language delay (he's ASD) and he loved learning Spanish in preschool. I do not think it hindered his speech therapy...in fact I think it helped. It got him speaking more and thinking about words and communication. He would answer his speech therapist in Spanish sometimes (which she did not know) which made speech therapy a little bit more fun for him (but I doubt for the therapist....) So, while it was a little aggravating for the speech therapist at times, it actually got him utilizing more vocabulary which was a major goal of ours! Nan
