Hi gaelle - yes the yoga poses count :) In my son's case I didn't realise he didn't imitate as he was my first. So for example when he hadn't started drinking out of a cup by himself I just taught him hand over hand (did it hand over hand for a week and then he 'got it'). It was only when I had my second that I realised that you don't usually have to do that and babies usually start drinking out of cups by copying those around them! We eventually managed to teach him to imitate by the age of about 8 and then he made loads of progress very quickly. He must have had some imitation at some stage as he would pretend to feed a doll or use a telephone.
He's 17 now, non-verbal, has severe learning disabilities and severe autism.
In terms of early signs there weren't that many but he regressed. So he lifted up arms to be picked up, played peek a boo and started with early words and lots of speech sounds - he then lost those speech sounds - but other skills (such as peekaboo) remained intact.
He's always been sociable and likes adults but he did used to ignore other children who approached him. He didn't point but would share attention - so for example if he saw a plane he would look at it, look at me while saying 'eehee' (plane) then look back at it. He's always been affectionate.
Imitation was not something that came easily to him (and that can make it hard to learn verbs). And he has a very severe verbal dyspraxia - so he has very good unserstanding now, but still no speech.
He was late but within usual range for crawling (13 months) and walking (17 months).
He had a very good understanding of nouns from a young age, but has gaps in understanding other bits of language. He is very good at guessing from context and key words. He has an exceptional memory although we didn't realise until google maps was invented and he then showed us he remembered things from the age of two.
Sorry this is rambling but early signs were:
1). No pointing
2). Difficulties following a point (could sort of do it sometimes)
3) Ropey at responding to name in busy places
4) he used to run objects past the corner of his eye
5) as a toddler he'd get stuck at thresholds - e.g. Moving from carpet to floorboards
6) he used to not let his legs/feet touch sand or grass so if we sat his down on grass or the beach would balance on his bum holding his legs off the ground.
I first noticed issues age 17 months and then drove myself mad wondering. The kids who were showing similar (or worse) signs than ds1 at the same age all went on to do an awful lot better than him. I think if you can park it a bit while getting on with whatever will help you be able to park it (for me that meant getting some SaLT exercises - and we did get a really good noun vocab doing that which has helped) then you can maybe reduce your worries as well. Honestly it was probably the worst time of my life - and although we didn't have a happy ending that was actually much easier to deal with emotionally than the wondering.
I was quite worried about ds3 for a while but found a way to park that and he is absolutely fine. An awful lot of kids who do show early issues go on to be fine - please don't assume our story is common.