Take our family. After my older two children began attending a foreign school, they became naturally quite fluent in English, and it was hard for English not to slip from their tongues when they came home. At such times I would urge them to converse in Chinese, adopting the slogan "English in school, Chinese at home."
以我本身為例，我那兩個大孩子因為平常上的是外國學校，外語流利自不在話下，回到家難免外語出口成章，這時我就勸他們以中文交談，使「上學去學外文、回到家來學中文」成為一個替換的模式，使孩子們習慣了一回到家來就是要使用中文。