I wish I knew his address.
但愿我知道他的地址就好了。相当于：
Im sorry I dont know his address.
很遗憾，我不知道他的地址。
I wish you could drive a car.
我真希望你会开车。相当于：
Im sorry you cant drive a car.
真可惜你不会开车。
I wish hs was coming with us.
我多希望他能跟我们一起来。相当于：
Im sorry he isnt coming with us.
真遗憾他不能跟我们一起来。
wish可用在过去时中而不改变虚拟的意思：
He wished he knew the address.
他多希望他知道那个地址。相当于：
He was sorry he didnt know the address.
他感到遗憾他不知道那个地址。
在间接引语中，虚拟过去时形式不用变化：
I wish I lived nearer my work，he said.
但愿我住得离工作地再近点，他说。相当于：
He said he wished he lived nearer his work.
他说但愿他能住得离工作地再近点。
B wish(that)+ 主语+ 过去完成时(虚拟语气)表示对过去的情况表示遗憾：
I wish(that) I hadnt spent so much money.
但愿我没花掉这么多钱就好了。相当于：
Im sorry I spent so much money.
真后悔我花去了这么多钱。
I wish you had written to him.
但愿你给他写过信就好了。相当于：
Im sorry you didnt write to him.
真遗憾你没有给他写信。
wished可代替wish而不改变虚拟的意思：
I wished I hadnt spent so much money.相当于：
I was sorry I had spent so much money.
(译文同上。)
变为间接引语时，这些动词不用变化：
I wished I had taken his advice，she said.
但愿我当时听了他的劝告就好了，她说。相当于：
She(said she) wished she had taken his advice.
她(说她)但愿当时听了他的劝告就好了。
C if only的用法与此完全相同。它的意思与 wish相同，只是比wish更生动：
If only we knew where to look for him!
如果我们知道上哪里去找他就好了!
If only she had asked someones advice!
假如她早请教别人一下就好了!