指过去：if I had been him
指现在：if I were him
指将来：if I were him; if I should be him ; if I were to be him
关于虚拟语气的“如果我是他”的问题
指过去：if I had been him
指现在：if I were him
指将来：if I were him; if I should be him ; if I were to be him