Researchers say that the Welsh language will "thrive" and by 2300 two-thirds of the population could be Welsh speakers.
More than a third of the world's 7,000 languages are currently classified as endangered and more than half are expected to go extinct by 2100. There are a number of strategies in place in those countries to boost the language.
The researchers have developed a model which can predict changes in proficiency levels over time and, ultimately, whether a given endangered language is on a long-term trajectory towards extinction or recovery. The data, published by the Royal Society, compares Welsh and te reo Māori, the indigenous language of New Zealand, as a case study. That shows that while Māori is on a pathway towards extinction, Welsh will "thrive in the long term".
The model is based on Welsh in Wales, where researchers say "significant development in bilingual and Welsh-medium education and the presence of the language throughout the public and private sectors have positively contributed to an increase in the number of Welsh speakers."