Do you know your animal sounds? Matthew does! The fact that he is able to articulate these sounds is a step toward speech.
Watch him in this video making animal sounds: sheep, cat, cow, dog, and pig. He skips the beginning consonants for all except the sheep and pig sounds. We're still working on getting him to articulate the m and w sounds and combine it with a vowel such as moo, meow, and woof. My personal favorite is his take on how a pig sounds.