Until a language explosion at age 2... these were all the *words* my son had:
mama
dada
baba
nana ... we call grandmothers nana in our family
up
down
peas (please)
tan-q (thankyou)
nigh nigh (night night)
tlangkeeng (blankie)
mmmmmm (either delicious "yum" or "I think not")
However, he communicated just FINE. An example: I'd ask if he'd like some more milk and he'd smile, come running forward, look expectant, raise up his baba (cup/bottle), and say "Peas", and after filling it he'd say "tan-q". A quirk of an eyebrow would be a question, a different kind of quirk would be skepticism. One kind of shrug meant one thing, another meant another. He could say a thousand words with his face and body. He had absolutely 0 problems being understood by people (even people outside of our family), and his comprehension was huge. He could point to colors, letters, numbers, parts of the body, follow directions (Kiddo, can you grab me the red shirt from your closet? ... would result in either the red shirt or him shaking his head no. Blue? And the blue shirt would appear.)
Now... all of this was spanning the YEAR. He wasn't even walking at 1, so I wasn't sending him for his shirt at 12 mo, but 18? Sure. Prior to red shirt it was things like put x in the garbage, or your shoes off the couch... then as he aged he got more precise.
Because he so clearly understood, and because he very clearly made himself understood... neither I nor his ped was concerned. And sure enough... language explosion right around age 2. So much so that that was our language "year". From speaking to reading. First 6 months or so was a real focus on fine motor (using his tongue, lips, and moderated breath to form words... and fine motor like finger and hand motions; pincer, mouse -computer-, coloring, typing, utensils), second 6 months was cognitive (taught himself to read, memorized poetry/ songs/ stories/ dialogue/ "funny things" people said, etc.). Then at 3 he dropped the fine motor and cognitive and switched into major emotional / intellectual meshing and independence seeking (aka the terrible 2s came a year late to our house), and moved right back into big motor (figuring out all the various ways he could hurtle his body throught space).