This paper explores the effects of different language home environments provided by English‐speaking and non‐English‐speaking migrant domestic workers (MDW) on Hong Kong children's ability to speak English. Results show that English‐speaking MDW in working‐mother households increase children's likelihood of speaking English by 12% if the mother in the household does not speak English but by 25% if the mother in the household is capable of speaking English. Non‐English‐speaking MDW, however, are found to have little such effects. Age and education are two qualities of English‐speaking MDW that are significantly associated with improvements in children's English‐speaking ability and their English school subject.