I must belatedly add...

I didn't mean to give the impression that 'Gah!' was the only thing Leo says - far from it. He'll sit and chat to you at great length about what he's doing, using a huge range and variety of 'words', even if they're words only he knows. He does tend to pick a mot du jour and use that to describe everything, and at the moment it's the G word, but last week it was something else, and it's just as likely to change again.

It reminds me of just before he started walking. He spent weeks standing, holding on to tables by one fingertip as if that was actually necessary, and then crawling off as if that was the first transport method that came to mind. When he started walking it was like he could have done it at any time, he just couldn't previously be bothered. I have a feeling that one of these days he's going to say, out of the blue, 'Dad, can I borrow the car? Oh, and twenty bucks?'

Mind you...

...he's getting better with animal noises.

Daddy points at dog. 'What does he say, Leo?'

Leo [in the manner of a barking dog]: 'hnnh, hnnh.'

'Very clever boy!' says Daddy, and points at Bonzo. 'And what does he say?'

Leo: emits short, high-pitched squeal, i.e. right on the money. Applause.

Mind you, you could point at a lamppost and Leo will sometimes tell you it says hnnh, hnnh too. But he does basically get it. You'll often be walking along with him when a quiet 'hnnh, hnnh' emerges from the pram. Sure enough there'll be a dog nearby, even if it's on a plastic base with a coin slot in its head.

What's that, Leo?

"Gah!" [points]

[Note: while he's particularly attentive to trains, trams and planes, able to sight them by mere reflection in a far shop window, by hearing a distant mechanical rumbling drifting on the breeze, or by spotting a silvery speck flying high overhead, the best we get by way of description is still 'Gah!'. Note this extraordinarily powerful word may also be used to indicate the presence of strawberries, tonka trucks, small plastic echidnas, Bonzo, his red metal Corvette, or anything else, including his mother.]