考点一：平行结构。基本要求是同等重要的或并列的句子成分要用同类的语法形式来表示，不能一会是不定式，一会是动名词，并通过用并列连词。尤其是当用and, but, both…and, neither…nor…, either…or…, not only…but also…, than等并列连词时，要注意使用平行结构。
I value a friend who is sweet, kind, and loving.
To know what is good and to do what is right is not the same thing.
He is well –known not only in China but also in many other countries.
It is easier to spend money than to maoke money.
考点二：情态动词＋完成式 表示对过去的推测。注意肯定和否定的不同含义。
The money has disappeared. Who could have taken it? 钱没了，会是谁拿了 ？
You screamed in your sleep last night. You must hve had a terrible dream.
你昨天晚上睡觉大喊大叫，你一定是在做恶梦。
You should have phoned me last night. 你昨晚应该给我打个大电话
（ 实际没有打。含有责备之意）
She shouldn’t have eaten those mushrooms yesterday. Mushrooms don’t agree with you.
她昨天本来不应该吃那些蘑菇，她不能吃蘑菇。
The restaurant was nearly empty. we needn’t have booked a table.