For the first six years of his life, Thomas Lim, the playwright and director of Grandmother Tongue, was more at home speaking Teochew than Mandarin.

Before he started primary school, he would spend most of his days with his Teochew-speaking grandmother, Tan Sian Tian.

"I became fluent in Mandarin only when I started to go to school, though I've hated it for a good part of my life. There is an unforgiving atmosphere towards our dialects and vernaculars. I feel like how 'Chinese' a person is, is measured by his 'Mandarin-ness'," says the 25-year-old drama educator.

"It's almost as if my ethnic identity has been whitewashed. The dialects spoken at home do not count as being Chinese and are considered uncivilised tongues even for the old and uneducated."

Teochew remains his bridge to his grandmother. Except for the occasional dashes of Hokkien and Malay, it is the only language he can use to communicate with her.

His play, Grandmother Tongue, traces the struggles of a young man (played by Tan Shou Chen) connecting with his dialect-speaking grandmother (Jalyn Han). It is based on his experience living with his grandmother, now 86, in the last year.

"While it's easy for me to read letters for her or understand what is being reported on the news, I've always struggled with my lack of means to communicate accurately and precisely what she wants to know," he says. "I've attempted to capture many of these struggles, both hers and mine, in this play."

Seniors who speak only dialects at times find themselves trapped in small, isolated lives.

Television programmes and newspapers are in languages they cannot comprehend. And as the use of dialects dwindles among the young, even conversations with grandchildren become rare, tricky affairs.

Lim was 13 when he joined the drama club at Catholic High, "not out of interest, but because I had a friend who was in the club".

But it became a lifelong passion, sparked all those years ago by his brush with playwright Haresh Sharma's coming-of-age tale Lanterns Never Go Out.

"I never expected theatre could be something about Singapore, something about us," says Lim. "So that got me reading and watching local works and excited about the possibilities of theatre."

Nur Asyiqin Mohamad Salleh

BOOK IT / GRANDMOTHER TONGUE

WHERE: Creative Cube, 1 McNally Street, Lasalle College of the Arts

WHEN: July 6 to 10, 8pm (Wednesday to Friday), 3 and 8pm (Saturday and Sunday)

ADMISSION: $35 (through Sistic, excludes booking fees)