Wait a little longer! My DD1 was EXACTLY the same. I posted pretty much the same thread as you 7 months ago. My DD1 at age 2 had a word explosion and now at 27 months says five word sentences. At 19 months, she had about two words but lots of expressions and gestures etc. I had everyone telling me to wait until age 2. Definitely wait a little bit. The main thing is, he understands you and does communicate