My DS14 drove me crazy as a toddler because he rarely spoke. He understood every word said to him and could follow complex directions at an extremely early age, but he just wouldn't put more than two words together. As a 3-year-old, in preschool, all of his friends would call the teacher by name, but would just point and and utter something that made him sound like Rocky after getting hit in the face repeatedly and losing some teeth. I was so worried that there was something terribly wrong, that I had him evaluated. The results showed his comprehension level to be that of 3rd/4th grader, and the speech therapist recommended that I simply be patient. He was simply soaking in so much of the world around him, that speech-wise he just couldn't keep up. She said that if he was still having issues in six months to see her again. At the end of that school year (2-months after testing), he was still not talking. Then, at some point during the summer something just clicked and he started speaking in whole paragraphs. He walked into his preschool, at the start of his 4-year-old year that fall, went up to the school's director and spent 15 straight minutes recounting our vacation to Pennsylvania Dutch country in great detail. I thought the poor woman was going to have a stroke, I don't think she had ever heard his voice in the two previous years he had been a student there! From that point on there was no stopping him. That year he learned to read, type, multiply, and more. Fast forward ten years and that same boy is now on schedule to graduate high school next year, and already has 30 college credits under his belt. So, please don't lose heart. Even if he is four before you have a conversation with him, it will be well worth the wait!