他昨天发生什么事了？

What happened to him yesterday

一楼的：你是字对字硬译，文法都不通；
二楼的：yesterday应该放在最后。
三楼的：有准确时间的情况下不能用完成时态。
故翻译成：What happened to him yesterday?

四楼的姐姐真牛

He said yesterday What happened?

What matter yesterday did he have?

What had happen to him yesterday?