In linguistics research, best practices for raising children is for a parent to speak to the child in his/her mother tongue. As a parent I have encountered comments made by concerned fellow parents and grandparents in an English-language preschool: “you’re speaking Indonesian to your kids, aren’t you afraid your children won’t be able to learn English?” My eldest child dispelled this myth by age 4. My three kids are quadrilingual. Indonesian parents, please speak Indonesian to your children.