I didn’t start talking until almost 2. I had some non-verbal communication like shaking my head and nodding, and the like, but very very little in the way of words. I turned out fine.
My daughter was an early talker, and continues to astound with her relatively advanced vocabulary for her age (she’s two). She is, however, not like her dad. I was a very late talker. My parents said I didn’t say much of anything until I was about 22 months old. Then I exploded and haven’t shut up since. 
don’t worry about it just yet, as long as everything else is good. Each kid reaches certain stages at different times.
I’ve been told that I didn’t talk understandably until I was three (and then wouldn’t shut up).
There was a neighbor child when I was growing up who only spoke in nonsense syllables way past two. Things like “Ack, ack, na, na, ackna, ackna.” Turned out that, as the youngest of four children he didn’t need anything else. All he had to do was point to something and utter a sound and someone would figure out what he wanted and give it to him. Also it would have been difficult to get a word in edgewise anyway. He had some days of frustration when everyone in the family stopped that behavior and insisted on an actual word, and then he was fine.
My sister did that with her daughter, replacing the word “grandma” with “Auntie Sarah” to address me. The girl’s response? “RAWR!!!”
It got a good chuckle out of everybody. She talks just fine these days.
What’s a “chook”? 
A baby duck or a baby chicken?
I’d check in with your doc, but my unprofessional opinion is that the kid is just going at his own pace, especially if he’s spot on everywhere else. Being able to imitate a chicken is particularly encouraging. (Wow, that sounds weird.)
Anyway, it could be that he just hasn’t experienced a need to communicate verbally when you’re able to understand what he wants when he uses gestures.
Does he say dada and mama?
I had the same problem with my little girl, even started a thread about it as well.
Now I need a thread about how to get her to shut up.
As for her Dad, I didn’t speak for quite a while and then when I started I had my own language which only my brother understood. This went on for about a year and I lost the language around 4-5 yo.
Someone asked that of my daughter when she was 2 and a new talker.
“What does your Mama say?”
“NO!”
One of the tricks I use with my 18-month old, is not to ask yes/no questions. “DO you want to go run around in the store, or go home?”. “Do you want strawberries with your yogurt, or grapes?”. Once she makes some attempt at responding, then I turn it into a yes/no question. I think it helps her language develop. Though maybe it also makes me a mean mommy.
The baby won’t talk is always followed by"how do you shut that kid up". She will make up for lost time.
Is he being stimulated to talk? Kids like to do what they want to do. If they can get by with the line of least resistance there’s no need to change.
I don’t have kids, but they seem to like me a lot. I’ve spent time with other people’s kids and the parents often come back how much they open up around me and like to play with me.
I found kids often behave differently toward people they LIKE. Of course they love and like their parents and grandparents but a friend is much different. Kids also seem to know when an adult is treating them with condescension.
Obviously it makes sense to take him in for a physical check up. If nothing is wrong, then see if he doesn’t talk or try to around new people. Or his friends at school. Then try games that require some sort of speech.
I didn’t talk until I was about 2 1/2. Apparently, this is quite common if you have older siblings who dote on you (like my big sister did). My dad had taken my sister to ballet and I wanted more cheese (which I could not reach) and my mom was occupied with the dishes. So, I said, ‘may I have that please?’ got my cheese and haven’t shut up since.
It’s possible with this being the first child/grandchild that the adults in the wee ones life are filling the same role that older siblings would. Try ignoring him for a while. See if it happens.
Single word “mama”/“dada”, or whatever word the kid happens to use - as long as it is used with clear and reproducible intent, is standard around 12mo of age. Word acquisition from that point on tends to occur in fits and starts, and there can therefore be quite a bit of variation in vocabulary between children of the same age. But the average 18mo old should have a handful of words. And no words whatsoever is distinctly not normal. All of the other evidence that you’ve given is reassuring that there is nothing cognitively the matter, but I would be concerned about a specific speech delay, and would strongly encourage your daughter to have your grandson evaluated sooner rather than later.
-ellis (pediatrician)
I remember my mom having a hard and fast rule - any kid who pointed and grunted was ignored. They had to say what they wanted. That made sense to me.
Kids do learn at their own pace, but if they learn that pointing works, why should they bother speaking? Just my unprofessional opinion…
Don’t worry. My daughter was speaking in full sentences at 11 months. My son still had a vocabulary of about a dozen words when he turned three. Today, both are equally literate, and the boy who started talking late is majoring in journalism with his own radio show on the college station and his own column in the school paper.
If you are worried, however, a visit to a speech therapist could help. Depending on where you live, it may be paid for by the school or the state.
My boy turned two in December. At the time he only said the typical mom, dad, bye sort of things clearly. There were many words he said that could only be interpreted by me (I’m with him 24/7). He wasn’t putting words together other than nigh-nigh mommy or bye-bye daddy. At his check-up, we mentioned his lack of intelligible speech. Doc told us that the boy should be evaluated only if we were worried about the lack of speech. He said the boy’s too busy experiencing his environment to talk about it. We aren’t worried so much as everyone else (except doc) is telling us that we should be. I confess that I nearly threw a celebration party the other day because the boy finally said horsh. For the longest time he said hor. You can only laugh till you pee when you’re on your hands and knees cleaning up the latest spill and your two-year old climbs on your back and shrieks, “yee-haw hor!”*
In the past couple of months the boy has had a verbal growth spurt. We appreciated our doctor’s advice. If the child’s parents are worried then they should have the child evaluated. If not, wait a few months and decide. My husband and I agreed that we would wait six months and if our boy’s speech hadn’t improved significantly we would take him in. Who knew it would only be a month before he made an effort at talking?
*The boy knows animal sounds so we also play “what sound does a (animal) make”. When asked what sound a mommy makes, the boy usually replies, “moooo.” I’m a bilingual horsh.
anecdotally, I didn’t talk until I was past 3 yrs old. Mother always claimed it was because I had a know-it-all older sister who did all my talking for me.
Does Grand-son have siblings that do all of his talking?
Thanks for all the info about your own experiences and the professional opinions too. I’ve decided not to push the issue just yet with my daughter, but to give little Zen another couple of months to get his stuff happening under his own steam. If by then he’s still not verbal, then I’ll get my Matriarch Cape on and urge her to get him evaluated.
Oh, and by the way, he DID woof today. Our puppy got spooked by something and ran out to the verandah where Zen and I were enjoying ths sun and set up a loud barking…after his initial astonishment, Zen joined in.
So now he’s bilingual…he speaks avian and canine.
Now you need to get him started on:
piscene (“What does a goldfish say?” - mouth: open, close,open,close…)
celestial (“What does an angel say?” [Handel’s Messiah] Ha…lelujah![/Handel’s Messiah])
What else we got?
(PS - for the confused - “chook” = “any chicken”. Or a very silly person, take your pick)