20 month old not talking one word at all.

[pomegranate1975]

My sisters son does not talk at all. He does not say not one word at all. She says she doesnt know why he doesnt talk at all.
I find it strange that he doesnt talk as usually all kids are saying some words by now.
He is also a grumpy child. He is always whining. She says he is never happy and always moody. He also doesnt sleep much during the day about 40min. He also wakes up 4am-6am everyday.
I think he might be autistic but not sure. I didnt want to tell her what i think as i could be wrong.

Ask her to take him to the health visitor to talk about his lack of speech. Depending on which area she lives in she may be able to self refer to a speech and language therapist.

If you and your DSis are concerned about autism you could look at something called M-CHAT which is a questionnaire that aims to give an indication of the possibility of autism for toddlers between 16 and 30 months.

Irrespective of the results of this though, you should encourage your sister to take her DS to the HV or GP to discuss this. It's probably better to get the ball rolling sooner than waiting for the next scheduled check up (possibly at 2 years ish).

Also, has your DSis had his hearing checked? Even a partial hearing loss could be making a big impact.

Thank you exbrightonbell, i did the questionnairre and it came up with 14, high risk of autism.
She already got his hearing checked and his hearing his fine.

I dont know how to approach her though, i think i might be told off.

Tbh, I think that the m-chat questionnaire should be filled out by his mum as she will have a better overall view of his behaviours.

If your DSis often talks to you about him, can you not just say that perhaps it's worth a trip to the GP/HV just to rule out any possible issues.

To be honest, your OP describes my NT nearly 6yo at that age. His speech is now perfect and he never ever shuts up. We were told to expect something by his birthday, but that it wouldn't even warrant a referral until 2.6, if no obvious problems with comprehension.