The authors investigated the language mothers use to regulate social conduct in family settings with their older (4- to 5-year-old) and younger (2-year-old) children. Samples of spontaneous conversations between British mothers and their children were collected over six months.  Twenty-five percent of mothers’ child directed speech was social regulatory, with significantly more such language directed to younger children. Although the most common kind of regulatory language directed to both children was imperative demands used prescriptively, data also suggest permission statements to younger children were used often to restrict activity, whereas permission statements to older children were used largely to permit activity. The authors discussed results with regard to maternal sensitivity to children’s developmental differences, conversational constraints in family settings, and possible cultural influences on speech styles.