Conversations with a 2 year old who doesn't talk :o)

My little boy is just over 2 and hardly speaks at all. This has caused me untold amounts of concern/frustration as both of his older sisters spoke very well, very early. I taught certain amounts of sign language to both of the girls but they hardly used it because they spoke so early. Thus I did not think it worth the time or effort to teach it to my boy........... Oh, the irony of it all, he is the one who needs it! We are both frustrated many times throughout the day at his inability to clearly communicate what he wants to. There are, however, certain things that he can and does communicate....... Currently his 2 favorite "conversations" are these:

#1 - Papa's Tractor

LM (little man, as I have not come up with any cute and clever bloggy names for us) : Pointing to himself -VRRROOOM (the noise he makes to talk about any and all motorized equipment and I am left to guess which piece of equip it is........ tractor, excavator, skidloader, etc......)
Me: Are you a tractor?
LM: Mmmhmmm
Me: Whose tractor are you?
LM: Papa's!
Me: Are you a BIG tractor or a little tractor?
LM: High pitched squeaky noises and shows me his fingers close together
Me: You are a little tractor?
LM: "Mmmhmm........ NO" Deep growly noises and arms spread are as far they can
Me: You are a BIG tractor?
LM: MMMMHMMM
Me: What color are you?
LM: BOO (Blue)

#2- His newest favorite is completely different...... NO MOTORIZED EQUIPMENT!!! :o) We, the entire family, are avid Beatrix Potter fans. I didn't realize how much attention he was paying until the other day when we played this (from The Tale of Mrs Tittlemouse):
LM: Shaking head with fingers in mouth "TEED"
Me: I declare! Mr Jackson..... No teeth? No teeth!
LM:Still shaking head with fingers in mouth "TEED, No"
ME: Would you like some Thistledown? It's very soft...... (while holding out hand to him)
LM: PPBBBTTTT (blowing the thistledown)
Me: MR JACKSON!!! (very animatedly in mock horror)
LM: Laughs and Squeals...... :o)

The above conversations are repeated countless times a day......... and he expects me to know my lines! :o) He plays it with the girls too...... I just love to hear them quoting the books. I think they can quote more lines than I can!