Have you spoken with your pediatrician about this delay in his verbal skills? Has he had ear infections? Okay....
I would call Scottish Rite Center for Childhood Language Disorders in Seattle. They are up on Capitol Hill. You can find them in the phone book and maybe listed as Kids Speak. These folks will help evaluate his needs and help him learn how to communicate. There is no charge for their services, they are affiliated with the Shriners. They work wonders. Our son did not talk until he was alomst 3 yrs old. He started attending Scottish Rite when he was 18 months old, as we noticed the delays. Our pediatrician sent us to Childrens, who evaluated him and told us he was dyspraxic, that and due to his ear infections, he hadn't heard any word the same way twice, so it was hard for him to mimic and learn language. The dyspraxia is small motor skill delays, and your mouth is small, fine motor skills. Needless to say we were overwhelmed. Childrens recommended speech therapy 2 times a week and told us that this would be ongoing until he was about 12-15 yrs old. I friend recommended Scottish Rite, as our health insurance at the time did not cover speech therapy. Scottish Rite worked with us, taught us how to talk and communicate with him and then started therapy with him. He graduated from Scottish Rite when he was 3.5 yrs old. He has graduated from high school, attends BCC, has a 3.86 gpa and will be transfering to WWU. He speaks like he was injected with a phonograph needle and the need for speech therapy until he was 12-15 yrs old never materialized.
For our family, our son, the therapists at Scottish Rite are miracle workers and gave us our son. Your little boy will be extremely frustrated if he can't get you to understand what he wants and needs. It makes life extremely difficult for all of you. I wish you well and hope you live in the Seattle area so you can take advantage of this great service. If not, they are also located in Yakima, Spokane and Portland.
Take good care!