The Class (15)

A year in the life of a tough Parisian classroom is engrossing and educational, not least in the way it breaks some cinematic rules

In one scene of Laurent Cantet's Oscar-nominated The Class, a Parisian schoolteacher struggles to explain the intricacies of French grammar to a roomful of teenagers. They're baffled: how are they supposed to know when to use everyday language, and when to delve into such rarefied tenses as the past subjunctive? In the end, all Monsieur can do is reassure them that it's all a matter of intuition.

Similarly, in the cinema, it's intuition that tells you what sort of film you're watching. You generally know when you're watching a documentary. But you might need to draw on your finer judgements to tell you whether you're dealing with a docu-drama, or a mock-doc, or any of those increasingly tricky subgenres that have flourished in recent years.

The Class may not represent a radically new approach to getting a purchase on elusive reality, but it represents a lively and ingenious engagement with the contemporary world. Cantet's film at first looks very much like a documentary record of a year in a Parisian junior high school, shot mainly in one classroom, focusing on one group of 14-to-15-year-olds and one teacher: it resembles a streamlined version of Frederick Wiseman's marathon "uncooked" records of American institutional life.

In fact, The Class is a cleverly artificed hybrid. It's shot and set in the Paris school where the film's pupils really study. The teachers are real too, all except one, who both is and isn't strictly real. François Marin is played by François Bégaudeau, author of the book Entre les Murs (Between the Walls), about a year teaching in just such a school. Although you'd never know it, such is the film's apparent looseness, The Class is a reasonably faithful dramatisation of Bégaudeau's novel – although whether the book is strictly a novel, or an impressionistic memoir, is another genre wrangle we needn't get into here.

At any rate, the film – co-scripted by Bégaudeau – is the result of a documentary-style approach to dramatic material, with Bégaudeau and his 20 or so students improvising around pre-planned situations. While the action may not be strictly real, it has a ring of casual actuality that's hard to fake. Seeing Bégaudeau in the classroom, you don't doubt for a moment that this is a world he's at home in: you can see it in the way he listens, the way he breaks up arguments or clamps down on pupils' time-wasting digressions.

The film begins with a staff meeting at which all the teachers introduce themselves, but thereafter, we barely get to know them, except for one man who explodes in an extraordinary rant of despair while his colleagues look on in baleful silence, as if they're all been there. In fact, it's the students who count, playing themselves, or so it seems – and by all accounts, it was largely their personalities that determined which of them become the focus of the drama. But Cantet's political agenda – this is very much a film about youth and race in contemporary France – also means that he's markedly less interested in the well-mannered white kids, who are more than adequately represented in French cinema. The pupils who emerge are those who carry a range of social issues: the African and Maghrebin boys who squabble about whether Mali or Morocco produces better footballers, or the duo of Khoumba (Rachel Régulier) and Esmeralda (Esmeralda Ouertani), who between them provide the most focused backchat.

Dramatic threads come in and out of focus. A new boy arrives, expelled from another school; class rebel Souleymane (Franck Keita) briefly blossoms under Marin's encouragement, but too late. A conflict comes to a head, sparked off by Marin rebuking two girls with the word "pétasse" (translated in the subtitles as "skank"): in a classroom where badinage flows freely in both directions, it seems that he has overstepped the mark.

Much of the film is built on passing moments that reveal much about the class and the outside world. The pupils complain because Marin illustrates a grammatical point with a sentence about Bill eating a burger: why Bill, they protest, rather than Aïsatta or Rachid?

We can't easily tell whether Bégaudeau is playing a version of himself, or he's creating a portrait of a certain kind of teacher – and it's not always clear whether Marin is a good teacher or not. Adopting a jocular sarcasm, downplaying his role as authority figure, he often seems to get it wrong, mock-sneering even when kids get it right. And there's a nice scene in which a gung-ho colleague tries to interest Marin in co-ordinating their lessons on the Enlightenment, and Marin gives him the brush-off in a way that could show his pupils a thing or two about surly apathy.

Only occasionally, you sense that a point is being scored. Towards the end, Esmeralda announces, to Marin's amazement, that she's been reading Plato's Republic: ah ha, you think, a cute touch to reassure us that these kids are motivated after all, and perhaps a suggestion that Marin's own approach is some sort of Socratic dialogue. Contrived as it seems, this moment is brought to life by the look of delighted, cocky triumph on Esmeralda's face. But just as you think the film is about to end on an upbeat note, another pupil tells Marin, with a look of absolute desolation, that she's learned nothing whatsoever all year. But there's no resolution to any of these dramas: closing shots of an empty classroom keeps a question mark hanging over the pupils' futures, hinting at the same cycle that will soon start all over again.

The very least you can say about this rich, stimulating film is that it has the zest of actuality that you get in the best documentaries, and only rarely in fictions that aspire to documentary urgency. Besides that, The Class is guaranteed to set you arguing about pedagogy, discipline, racial and social identity: you could show this film in Hackney, Brooklyn, Shanghai or Baghdad and it would have much the same currency. The Class is no way didactic, but it's certainly educational, letting us ask the questions, but providing no cut-and-dried answers – not even about when you should use the past subjunctive.