it's strange that he (know）so much about me为什么不能knows

it's strange that he (know）so much about me为什么不能knows
it's strange that he (know）so much about me为什么不能knows

it's strange that he (know）so much about me为什么不能knows
这动词应该是 knows
词性要和前面的 he 一致.,
用 knew （过去式）也可以,
当然 should know 也没有错.

虚拟语气should加原型should省略