TWO things that recently came out of my son's mouth reminded me of the thorny issue of race - and the importance of talking to our kids about it.

Last week, five-year-old Julian bounded into his grandmother's kitchen, where our domestic helpers were preparing dinner, and hailed them.

"Hello, Filipinos!" he shouted cheerily. Upon overhearing this in the living room, my instinct was to instruct: "Don't say that! It's rude!"

A few days later, when we were dropping off Julian's best friend, D, and his mum after school, my boy rolled down the window and yelled: "Goodbye, Indian boy!"

I wanted the earth to swallow me up, and tried to shush him. Meanwhile, D and his mum, who had moved here from the Indian state of Kerala, looked on - amused at how I was getting so wound up - as we drove away.

I knew he didn't mean anything ill by those salutations. We had been teaching him about countries and cultures, and his interest was piqued. He spent his free time poring over books about flags, playing a country quiz game on the iPad and looking up national landmarks on Wikipedia.

But, as D and his mother disappeared from my rear-view mirror, I gradually brought the car to a stop by the side of the road and proceeded to talk gently to Julian.

"It's not nice to call people by their nationalities," I said, trying my best to explain the fine line between stating the obvious and offending people by pointing out physical differences.

"Would you like it if people kept calling you, 'Hey Chinese!'?" I added, trying to give him an example to relate to. "It's not wrong to say that, but it's just more polite to call people by their names."

The boy nodded quietly - not quite sure what he did wrong.

I then tried to make the distinction for him between addressing people in a group you are part of, and one that you are not. (For instance, it is perfectly fine to yell out: "My fellow Singaporeans!")

For good measure, I added: "If you keep shouting things like that, when you grow up, people might think you are making fun of them, and they might get very upset."

Looking subdued, my son heard me out as I told him that if he was curious, it was better to speak one-on-one with a friend about his national or racial identity, and ask questions.

As my political correctness kicked into overdrive, I noticed that I had parked next to a police car inadvertently - and Julian was starting to look worried that he might get arrested for a casual remark.

With Racial Harmony Day just behind us (that's on July 21, for those of you who do not celebrate it), and National Day ahead, with its message of "one people, one nation, one Singapore", I couldn't help turning the two incidents over in my mind.

Did I over-react? But, surely, it is better to nip Julian's habit of saying these potentially embarrassing things in the bud?

Or am I simply imposing my adult sensibilities on an astute child who is figuring out that the world is made up of different people?

My super-mum friend, M, who is of Scottish-Chinese heritage, giggled when I told her about Julian's exploits.

"I don't mind if you say, 'Hello, Eurasian woman!' to me," she quipped.

I was horrified. "I'd never dream of reducing you to a socio-political category!" I retorted.

Later, when I had calmed down, I realised that there was sense in what my friend said. Sometimes, like with the birds and the bees, there is no need to shy away from talking about how the world is made up of different people who are proud of who they are.

As American educator and race-relations expert, Dr Beverly Tatum, advised on Parenting.com, look for teaching moments about race, make the message age-appropriate, accept that prejudiced comments happen and that doesn't mean your child is a racist, and - most importantly - be a role model.

I'm glad I had that talk with my son. And we will be discussing the issue more in future - minus my freaking out first.

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