Aldo Williams: A brilliant film – and a tribute to teachers

If you're a secondary teacher, you're lucky if it's just one class and unlucky if it's two or more. These are the classes that utterly, miserably, wretchedly, exhaust you. End of term can't come soon enough. In fact, in your worst moments maybe you have been thinking that the end of the school year and a change of job can't come soon enough – maybe to the private sector, where you know such grimness just doesn't occur.

But didn't you come into teaching to make a difference to kids like this? Well, that was then and this is now and, as TS Eliot must have written just after taking 10C: "Humankind cannot bear very much reality." You've probably already had more than enough of it this year.

But, before you give in your notice, I have a suggestion – go and see the movie The Class, or get the DVD. You've probably heard of it – teacher in not very pleasant Paris suburb struggles with one particular Year Ten class. It's all messy failures – theirs and his. Muzzy successes, ditto. This film is certainly not of the "committed teacher, uncommitted class, and piercing white light of learning wins through in the final reel" genre, though the committed and uncommitted certainly fill their usual roles.

So this class, these teenagers, are unruly, sulky, inattentive, uncaring, winding each other up and – their favourite sport – winding the teacher up good and tight. But of course it isn't the entire class, and beyond the three or four loudest and most disruptive we see, but rarely hear, the rest – the ones who make no fuss, who just want to learn, who wish the noisy would shut up, and who make you feel even worse than you might when you realise that they never get from you the attention they need.

The extraordinary achievement of the film is that although it was scripted to a degree, the pupils aren't actors and the teacher is the teacher who wrote the book that became the film. What we see unfolding before us is every bottom set of that age that you have ever taught, and there's you, holding on by the skin of your teeth, out at the front and up and down the rows – more or less losing it, or more or less winning it.

Our teacher tries to teach the syllabus – an aspect of the subjunctive in one lesson (how the French love their grammar). But the lesson's a failure because, as the class point out to him in the brutal fashion you're probably very used to, the applications he suggests are going to be of no likely use to them at any time, ever.

The school itself seems typical, too. It is by no means failing, and is probably averagely successful. There are boundaries that are more or less accepted by the class, so desks and chairs don't fly round the room or out the window, as they did in one school I taught in some years back. And there are times when all the class get their heads down and write, and achieve something, and are proud of it. The "highlight" of the film is a possibly unjust permanent exclusion. Our teacher doesn't come out of that at all well.

So why should you see this film? You suffer these kids in the week, so why should you watch them strutting their sad, shallow, raucous stuff in the comfort of your own home? You should see it because it's probably one of the few ways you will really see the real good you are doing. No, it's not as much good as you would like, but this film makes it pretty clear that the good some of them get from their teacher, in spite of his failures, is a lot more than they will ever get without him.

Let me spell it out for you. As a teacher, you are probably one of the few decent adults some of these teenagers will ever meet. You're not drunk, you're not on drugs, you don't beat them or abuse them. You expect order, decency and work back from them (though you may not get it).

You have time for them, you're prepared to listen to them. You show them you care about them and you want to do all this through the medium of teaching them things that might make it a little easier for some of them at least to make more of a go of life than the narrow, abusive and restricted world they inhabit will ever allow them without you. See this film, learn that lesson. They may not need the subjunctive, but they do need you.

The writer is a former teacher at a comprehensive school