Rosemary's baby
In English, we often use an apostrophe followed by an s to express possession : instead of the baby of Rosemary , we say Rosemary’s baby . That means Rosemary has a baby. We normally use this structure with people and animals, to indicate that they have something – the baby’s name, the girl’s name, the cat’s name . However, we say ‘ the name of the girl who had the baby ’ – because ‘ the girl who had the baby’ is a long phrase. Sometimes we find one ’s after another: The baby’s mother’s name is Rosemary . ( → Here the baby has a mother, and the mother has a name.) We must be careful with the spelling. When a noun is plural and ends with an -s , we only write an apostrophe: my parents’ house . So I can talk about my friend’s house (if the house belongs to one friend), or my friends’ house (if it belongs to more than one friend). When a noun is plural but doesn’t end with an –s , we write the apostrophe followed by an s : the children’s bedroom, wo