Come rain or shine, a group of young children meet at Bukit Batok Nature Park on a weekly basis, where they look for fish in the streams, spot monkeys and listen to stories told in Mandarin.

These two-hour sessions of language immersion in the outdoors are organised by Treebubs, a Mandarin parent-accompanied playgroup that started last month.

Co-founder Stephanie Lim, 30, believes the authentic environment makes Mandarin come to life.

"Instead of seeing a photograph of a tree or a stylised representation, they can see its true scale, listen to the leaves rustling and to the cicadas that live in it," said the former civil servant. "These direct sensory experiences allow them to forge a strong connection with nature, and the teachers describe these spontaneous interactions in Mandarin to build the children's vocabulary in an organic way."

In the belief that less structured play results in more effective learning, the children, aged 18 months to four years old, are given space to play with water or use fallen leaves and sticks. The group's two teachers take the kids on nature trails to observe and discuss the plants and animals. Accompanying parents are encouraged to speak Mandarin .

These sessions shift to sheltered places in case of heavy rain, but even light rain can bring about a meaningful interaction with nature for the children, who put on raincoats and collect rainwater in jars.

There has been a growing interest in the programme, which now has four to five children. A weekend class will be launched next month.

"We take advantage of their innate curiosity and sense of wonder at the natural world to introduce wide-ranging dialogues," said Ms Lim. "This makes learning Mandarin meaningful rather than a chore."

Yuen Sin