i went thru the same with my eldest DS...i was worried he wasnt saying enough words etc but he is now 4 and half and wont keep quiet

my 2nd DS who is 2 yrs 2 months, says

Spider
Choo choo (train)
Skye
Mama (grandma)
Dadda
Mumma
Wow
Yay


But he will get there in his own time and he understand me perfectly....Each kid is different and leanrs at different rates i think if you just keep talking to him and getting him to repeat the words