he's sam and amy's friend.

he's sam and amy's friend. he's sam and amy's friend.we bought ise creans.then we went John is Sam and Amy's friend.是否有语法错误? Sam and Amy's clothes are wet.为什么只在Amy的后面加名词所有格's? Yesterday Lingling went to Sam and Amy's school.用这句话提问 "He has shorter hair than Sam.And he's calmer than Sam . "He has shorter hair than Sam .And he's calmer than Sam."是什么 He San and Amy friend.翻译中文 用be动词的适当形式填空:sam's and amy's room___over there.The little do l went to sam and amy's school yesterday（改成否定句）答对就给财富值 he's my friend, He's John friend?