One of the most fascinating parts of watching a toddler grow up is to observe the development of language, syntax and general verbal communication, in particular the rate at which this accelerates around the age of two.

Now I know there’s an element of blinkered parental pride talking here, but Isaac has always been pretty advanced when it comes to his verbal communication skills. Child development experts say the average two year old should have a vocabulary of around 300 words. Shortly after his second birthday, Heather and I had a go at writing down all the words Zac could already say: we stopped counting at 800-plus, a vocabulary which included such random words as ‘kiwi’ (as in fruit).

But since then, as with all two year olds, he has taken ever greater strides forward. Often it’s a case of parroting back words and phrases which he hears used by us, his grandparents or at nursery, which he carefully repeats back with the correct inflection – or exaggerated to comic effect, as in his use of  “Oh, my goodness!”

At other times, he has demonstrated that he can take something I say, apply some logical processes to it, and come back with a response using related vocabulary in the correct context. For instance, from last weekend:

Me (putting Zac into his car seat): “Let’s go to the tip, then I’ll take you to the swings and the slides.”

Zac: “No, Daddy. Park first, recycling later.”

How cool is that? (Although I worry about the fact he is already a more competent negotiator than I am.)

Most impressive of all, he is now stringing together complete sentences which frequently employ grammatically correct pronouns, prepositions and other elements of speech. (For example, “Daddy, let’s drive to London to see Grandma and Grandpa.”) In the space of three or four months, it has been noticeable that we no longer speak to him in pidgin English but in full sentences – and we now take it for granted that he will understand and be able to respond in most instances.

Take the following exchange, which took place at around 4.45am (grrr) today:

Me: “Isaac, have you done a poo?”

Zac: “No, Daddy.”

Me (after smelling him): “Isaac, are you sure?”

Zac: (furrows his brow in thoughtful contemplation): “Sorry, Daddy. Isaac’s not doing a poo. Isaac’s already done a poo. Silly me. Change my nappy, Daddy.”

Even bleary-eyed and three-quarters asleep, it’s impossible not to break into a smile and to feel my chest swelling with pride at times like this.

I know that the parents of many other two and three year olds will also be having the exact same experiences and emotions watching their children surpassing their own linguistic milestones. It’s one of those big things that makes kids so much fun, isn’t it?