Hiring locals to teach mother tongue languages in pre-schools remains a challenge, even as more parents want their children to be bilingual.
Locals currently make up 3,300 of the 5,700 language teachers in pre-schools, according to the Early Childhood Development Agency.
Anecdotally, pre-school operators say it is not easy to recruit Singaporeans for the job. Mr Ng Yi Xian, executive director of EtonHouse International Education Group, said: "As this talent pool can be quite limited in Singapore, we therefore have to recruit from overseas."
Eighty per cent of EtonHouse's Chinese language teachers are from China. The rest are locals.
Dr T. Chandroo, chief executive of pre-school chain Modern Montessori International, said most younger people speak English and would not opt for Mandarin early childhood courses. Some 75 per cent of its 20 Chinese language teachers are foreigners.
Ms Thian Ai Ling, deputy general manager of My First Skool, said the base pool of graduates in Singapore who are qualified to teach Chinese is "not big to begin with" and they have other job options like joining Ministry of Education schools.
Similarly, a spokesman for PAP Community Foundation Sparkletots said it has recruited foreign teachers since 2010 to meet the growing need.
There is a local pipeline of pre-school teachers, but they need time to be trained, said Mr Ang Hin Kee, MP for Ang Mo Kio GRC and executive secretary of the Education Services Union, which represents pre-school teachers.
Dr Intan Azura Mokhtar, also an MP for Ang Mo Kio GRC, voiced concern in Parliament last November that a sizeable proportion of foreign mother tongue language teachers in pre-schools could affect children's language learning if they have limited understanding of local culture.
But pre-school operators said many have settled in Singapore with their families, and some even become permanent residents.
Being native speakers of Mandarin, they are also fluent in Chinese traditions such as calligraphy.
Ms Fiona Walker, chief executive of Julia Gabriel Education, said with more locals speaking English as their first language, their Mandarin standard may not be as good.
"In pre-school, especially, where so much of the engagement involves singing and nursery rhymes, it can be quite hard for locals as it's not teaching a language formally."
The group has 49 Chinese teachers, all from abroad, across its pre-schools and enrichment classes.
Mrs Tammy Calabro approves of her six-year-old daughter being taught Chinese by native speakers at Chengzhu Mandarin Kindergarten, which comes under Julia Gabriel Education.
"I don't think it's a problem. In fact, their Chinese is so much more poetic and flowery, and it's good to let the kids listen to them," said the restaurant owner in her 30s.
"The teachers are educated and not just good in Chinese - they also know how to deal with kids."