You can use next door’s to indicate that something belongs to the person or people who live in the house to the right or left of your own.
...next door’s dog.
DET
You can use next door’s to indicate that something belongs to the person or people who live in the house to the right or left of your own.
...next door’s dog.
DET
Collins COBUILD Advanced Learner's English Dictionary. Английский словарь Коллинз COBUILD для изучающих язык на продвинутом уровне. 2006