It seems as though modern speech recognition (e.g., through Android, iOS phones) make use of grammar or sentence structure. (e.g., it might have a tough time distinguishing between "grammar" and "grandma" but can distinguish between "I'm going to see grandma" and "I'm reading a book on english grammar". (yes, I just tried it with my Android phone with vLingo app)
That is much improved (with Speaker Independent SR (i.e., no training)) over what I experienced with Dragon Dictate even using Speaker Dependent SR (with 30m of training).
So, I'm wondering whether my guess is right: When did the commercially available SR software start using grammar and sentence structure to "guess" the right speech?