Ireland ? The traditional Irish language is everywhere this time of year, emblazoned on green T-shirts and echoing through pubs. But Irish, often called Gaelic in the United States, is one of thousands of “endangered languages” worldwide. Though it is Ireland’s official tongue, there are only about 30,000 fluent speakers left, down from 250,000 when the country was founded in 1922.

Irish schools teach the language as a core subject, but outside a few enclaves in western Ireland, it is relatively rare for families to speak it at home.

“There’s the gap between being able to speak Irish and actually speaking it on a daily basis,” said Brian O’Conchubhair, an assistant professor of Irish studies at the University of Notre Dame who grew up learning Irish in school. “It’s very hard to find it in the cities; it’s like a hidden culture.”

Irish is expected to survive at least through this century, but half of the world’s almost 7,000 remaining languages may disappear by 2100, experts say.