My DD is nearly one. Not crawling and not showing she understands any speech. Very busy and delightful. Only a fool would think there was anything wrong with her.
but
My friend brought her DD to visit at exactly the same age. When my friend asked her DD how she was going to blow out the candles on her birthday cake (and there was no signposting of the phrase at all), the child puffed and puffed. Then she asked what the ducks said and the child quacked. Then the cows...
Any thoughts beyond 'they all get there eventually' etc etc?