It rolls, it lilts, and it rasps. It begins in the back of the throat, turns around the mouth, then it sings. It is also the tongue of the country I come from, a country that I have long left, along with many other pobol Gymraeg. I barely speak the language now – I had to call my father to check that last sentence – but Welsh is something I care about deeply. Even though it looks as if I have become part of its steady decline.

Figures from the Comprehensive Welsh Language Board released this week paint a dark picture. The number of Welsh speakers moving out of the country, or dying, every year – 11,700 in total – is overtaking those who are left and those who are learning. And there are many more learning than there used to be.

Since the 1993 Welsh Language Act, Welsh has been compulsory in schools to 16, bilingual signs have arrived on Welsh streets, and polyglotism has swept into officialdom – a phenomenon boosted further when devolution gave Wales an assembly. Super Furry Animals even got a Welsh language LP, Mwng ("Mane"), into the top 20 in 2000. But these successes – I know now – are conspicuous ones. Deeper problems lie in how Welsh is used in the long term.

Cynics might question this report's timing. After all, the Board is being discontinued next month, to be replaced by one assembly-appointed commissioner. This week also marks the 50th anniversary of poet-activist Saunders Lewis's speech about the fate of his tongue. Warning that Welsh would "cease to be the language of a living community" (in shops, streets, pubs and clubs) in half a century (that's now), his words led to the institution of the Welsh Language Society and a Welsh Secretary of State. So there are shades of a political point being made in 2012, and a desire for more money.

But how widely does Welsh actually live, when we consider Lewis's terms? If its speakers switch to English in communal situations – as they often do, in my experience – is it living at all? An even more pressing report finding is the decrease in "the likelihood of one Welsh speaker meeting another at random". Which suggests that Welsh is often confined to the classroom, or tight circles of family and friends. This does not dent its importance to the people who speak it, but it considerably slows its potential to travel.

And this is the biggest risk facing Welsh, or any other minority language. Whether you still live back home or are a deserter like me, it's easy to think the language will always be there. You forget that things can collapse without care, that walls can tumble down. Dwelling in the nostalgia of a language, or its romantic rhythms, is all too easy. Being active is difficult, but active we must be – to make sure our languages roll, lilt and rasp, forever, am byth.

www.juderogers.com