All but one相关的语法

请问,all but one后面不用介词、直接加名词的话,名词应该用单数还是复数呢?比如:
All but one child are living together;
All but one children are living together.
这两句话哪句才是正确的呢?究竟应该是all来修饰后面的名词,还是one来修饰呢?后面的谓语的数我是知道的,不论如何,都是复数.关键就是前半部分.如果是all来修饰名词,那么这句话的主语中心词就是children,但如果是one来修饰,那么all就会是中心词,作名词用.
答：前者正确,后者错误.
分析：这两句中but是介词.1句中主语是All,but one child这个介词短语提前,不提前是：
All are living together but one child.
第二句,如果介词短语还原则为：All children are living together but one.如果提前,则应提前到主语all children和谓语动词之前：All children but one are living together.
第二句中的all是限定词,和his的用法一样.比如：His faher is climing the hill with the students.
with the students 是介词短语,可以提前,但总不能插入his 和father之间吧?只能是：Hi father with the students is climing the hill.