There are few teachers that make a real difference to a child's life. Alistair Weakley was one teacher who helped shape mine.

At St. Andrews College in Grahamstown he began the school's first Xhosa class in those all white days of 1975.

Xhosa, the mother tongue of Nelson Mandela is the second most widely spoken language in South Africa after Zulu.

I remember so well the first day Alistair walked into our classroom. He was a powerful young man in his early 20s whose fashionably long brown hair and sideburns looked incongruous with his black teaching gown.

Idolised by the children

Ali, as we called him when he was out of earshot, was a hero to us 14-year-olds. He was a brilliant rugby player. He was funny. And he seemed to know all about things like women.

In that far away South Africa, he was outwardly all that we white boys ever thought we wanted to be. But inwardly Ali had one thing that made him different from so many of our role models - he spoke fluent Xhosa. And he had zero tolerance for the racism that was common and so accepted in our world then.

Well, I began to think, if Ali doesn't like it, then it must be wrong. Sadly, despite Ali's best efforts, my Xhosa today is not fluent but what has remained with me over all those years is that fascination and respect he had for Xhosa culture that he communicated to us through his deep understanding of the language.

In those hard cold days of apartheid, to be given a small glimpse of the world of black people was a revelation to me.

Ali challenged the received prejudices of our white world and got us to question them as well. With his gown and his always breaking chalk and his untidy hair, he opened a door for me and sent me on a journey, both into the world and ultimately into my own heart. I never saw him again, from the day I left school but I was shocked when I heard the news of his killing in April 1993.

Irony of his death was bitter

Only three days after the murder of Chris Hani, the head of the South African Communist party and an immensely popular leader in the black community. Alistair and his brother Glenn were on their way home from a fishing trip when they were ambushed by four black youths wielding automatic rifles.

I was surprised at the depth of my own reaction. It brought the bleakness of those days closer to me than I had ever expected. That a man who had set me on the road to believing in a non-racial future for South Africa should have been one of those killed in revenge for Chris Hani.

The irony of it was bitter. I thought of Ali a few days later when I was standing outside the stadium in Soweto covering Chris Hani's funeral and watching the smoke from the fires of rage billow into the sky.

I have covered ten different wars as a journalist but I have never been so terrified in my life as I was that day. It is one thing to report on someone else's chaos and suffering but to watch my own country teeter on the brink of civil war drove me to the closest I have ever been to cracking up.

The memory of Ali Weakley and what he had taught me in that hot summer class from so long ago was one reason I was able to look beyond my own despair and to believe there was another way for South Africa, that we would overcome those days that had brought us to the edge of horror.

His killers should know

Ali has been dead for over five years. I wish he was alive but because he is not, I honour his memory and will do so for the rest of my life. I want his killers to know what kind of a man he was.

At the amnesty hearing one of the killers, Mlulamisi Maxhayi, said of the actions of the time: "We decided to kill the white people because they were a symbol of apartheid."

But Fundisile Guleni, another of the killers, also said: "We are so sorry for the families and would like to apologise to all of those affected by our actions."

I am angry, very angry that they killed Ali. But personally, I do forgive them. I say that in the full humility of knowing that it is easy for me to do so.

And I do not wish to intrude on the grief of his family but I want to forgive them because one thing I have learnt from other peoples' wars is that hatred is a choice but so is forgiveness, and it is one I wish to make in my own life.

Above all, I want South Africa to know what kind of a man we lost in Ali Weakley. I want somehow to keep the lessons he taught me alive because we still have a long way to go before we can truly say that as black and white, we understand and trust each other.