（a）I could have lent you the money.
(b) She could not have been more than sixteen.
请问这两个句子中的 could + 动词不定式完成式具有什么含义？
在陈述语气里，could + 动词不定式完成式常常用来表达下面两种含义：
A. 表示某事在过去本有可能发生,但事实上并未发生。在这一基本含义下,可用于表示埋怨或训斥:
-
Then perhaps we could have smoothed things down in a reasonable fashion. (Snow) 那时也许我们能用合理的方式把事情处理好。
-
You needn't have cooked it. We could have eaten it raw. (PEG) 你本不必去煮熟它,我们原可以生吃的。
-
You could have helped me! 你本来能够帮帮我的嘛!
-
You could have warned me she was coming. 你本应该告诉我她要来的。
-
I hate to say this about a Republican, but Nixon could have been a wonderful President. (B. Clinton, My Life) 我不愿意这样评论一位共和党人，但尼克松本来可以做一个很棒的总统。（《我的生活》）
B. 表示对过去可能发生的事件的一种推测：
-
She could have gone off with some friends. (PEU) 她可能跟几个朋友出去了。
-
This glass is cracked. Someone could have dropped it. 这个玻璃杯破了。可能是谁把它掉在地上了。
-
"The money has disappeared! Who could have taken it?"
"Tom could have(taken it); he was here alone yesterday." (PEG)
“钱不见了！能是谁拿走了呢？”
“可能是汤姆拿走了,昨天只有他一个人在这里。”
-
The letter could have got lost in the post. (OGEG) 那封信可能在邮递中丢失了。
-
You easily could have left your hotel room unseen. (Dan Brown, The Da Vinci Code) 你可能在别人看不到的情况下轻易地离开了酒店。(《达·芬奇密码》)
C. 表示过去实际上的可能性：
That I had friends and acquaintances from such a diverse group of people when I was young may seem normal today, but in 1950s Arkansas, it could have happened only in Hot Springs. (B. Clinton, My Life) 小时候，在如此形形色色的人群中，我都拥有朋友和熟人。现在看来没什么，可在20世纪50年代的阿肯色州，只有温泉城才有这样的可能。（《我的生活》）
请做下面的英语试题：
- —I stayed at a hotel while in New York.
—Oh, did you? You ____ with Barbara.
A. could have stayed B. could stay C. would stay D. must have stayed(全国高考,98-19)
- —We could have walked to the station; it was so near.
——Yes. A taxi ____ at all necessary. A. wasn't B. hadn't been C. wouldn't D. won't be(全国高考,92-26)
- My English-Chinese dictionary has disappeared. Who ____ have taken it? A. should B. must C. could D. would(上海高考,03春-24)
could + have done 在虚拟语气中的用法，见 subjunctive mood 。