英语翻译（解释）

很明显，第一个是对的，第二个是错的。
at school是副词，只能用be动词连用构成主系表结构。如：He was at school yesterday.
不能说did...at school。因为did是助动词，后面必须跟实意动词，很明显，第二个句子中没有实意动词（at是介词，school是名词）。但可以这么说：Did hegoto school yesterday?

Was he at school yesterday?才是对的 陈诉句为He was he at school yesterday. 谓语动词为系动词，该句改疑问句为系动词提前。 如果谓语动词为行为动词才是要用到助动词do的，比如说 he had a good time yesterday. 此句改疑问句为 Did he have a good time yesterday.

他昨天在学校吗？他昨天在学校吗？
都一样啊，亲！

was
陈述句式 He was at school yesterday

第一句对，第二句错。he 应该用 has, is , does...不应该用 do，have ...

其实都可以，但第一个比较高级