when did the express arrive here?it arrived here at last night.语法正确吗不加at可以吗

last night 前面不能用 at。一般说来，at 后面接具体几点钟或相当于某时刻的一个时间，如 at eight o'clock, at noon, at night.

不能用 at. 用 at 的时候，你要说个具体时间。比如，He arrived here at two. Or. It arrived here last night at eight pm.

arrive后面不可+地点副词,here,there.overthere等.另外last night前面部需要+介词.
at后面+地方或者时间点.
改为:When did the express arrive?It arrived last night.

there is noproblem in gramer。
you can use “at”，if you do not use it ，the sentence is also right。

可以