有下面两个句了:
Both of my kids are still in school. 我的两个孩子都还在念书。
They formed a band when they were still at school. 他们还在读书的时候就组建了一个乐队。
好像 in school 和 at school 都表示“读书”“念书”,它们有区别吗?
Kate is at school. 凯特在上学。(英国英语)
Kate is in school. 凯特在上学。(美国英语)
——摘自《薄冰英语惯用法词典》
恐怕要补充一下:表示在学校,不在家里。英国英语用 at, in 皆可,即 Kate is at / in school,美国英语只可用 Kate is at school。