New Zealand has invested heavily in its unique language. Pre-school kohanga reo started in 1982. Primary schools, te kura kaupapa Maori, began to be set up a few years later.

Maori radio stations were launched about the same time. The Maori television channel began broadcasting in 2004. Yet the number of fluent speakers continues to decline.

The educational efforts of the past 25 years have not produced sufficient numbers of Maori speakers to replace those dying. After an initial surge of enrolments in kohanga and kura, enthusiasm among Maori has waned.

Nearly half of all Maori children receiving pre-school education in 1993 were in kohanga; by 2002 that had fallen to under a third. The number of centres fell from 809 in 1993 to 545 in 2002 and 464 last year.

The Waitangi Tribunal is just the latest agency to note the decline. The Maori Language Commission has been sounding a warning in its language week promotions, and the Minister of Maori Affairs, Pita Sharples, set up an inquiry in July. His panel is going around the country gathering information for a review of the Government's Maori language strategy.

It is already evident that the tribunal and the minister disagree on the cause of the problem. In a letter to Dr Sharples prefacing the tribunal's report last week, its presiding officer, Justice Joe Williams, blames failures of public policy.

"While Maori today must guard against complacency," he writes, "the reo 'movement' has been weakened more by the governmental failure to give it adequate oxygen and support than by any Maori rejection of their language."

Receiving the report, Dr Sharples said governments could only do do much. "It's really got to be by the people," he said. "The responsibility lies squarely with the people. It is about getting the language into homes and people talking it. That's how it will survive."

Dr Sharples' view invites more novel solutions than those the tribunal has proposed, which sound like more of the same. It wants more Maori-speaking teachers, more opportunities to use te reo in the courts and other public agencies. It wants more evidence of a Crown-Maori partnership for preserving the language and a better strategy to motivate Maori at the grassroots.

Many of the children who entered kohanga reo in 1985 are now old enough to have pre-school children themselves. The figures suggest they are not sending the children to kohanga reo in the same numbers. Inquiries into the language need to talk to them directly. It may be that a shortage of teachers denied them places at kura kaupapa, and that their use of the language atrophied in higher education. But normally, a language acquired in infancy is not readily forgotten.

Inquiries need to consider whether the language is being promoted in the wrong way. The agencies charged with its promotion may have been too serious at times about its purity and preservation. A living language is never static. It is always borrowing and inventing new words and inflections. A language with an oral rather than written heritage may be particularly hard to preserve in pure form.

Maori language is not going to disappear. Dedicated scholars will keep it alive no matter how few households continue to use it. But its use should be more than ritualistic and obligatory.

To thrive a language must be popular. Maori needs to be promoted as New Zealand's unique possession, a distinction that could help bind and define us. If all New Zealanders emerged from primary school with at least a smattering of a language that nobody else in the world knew we would probably enjoy it and quickly come to cherish it.