We shouted at him, but he didn’t hear.(改错)

We shouted to him, but he didn’t hear.
我们喊他，但他没听到。
shout at ...冲...喊叫（恶意的，目的是责备）
shout to... 喊......（善意的，目的是让对方听到）

是介词用错了，应该是

We shouted to him, but he didn’t hear.

to 表示朝某个方向喊叫

at 表示面对面吵嚷叫喊

We shouted at him, but he didn’t hear US

没错