否定：
全部否定和部分否定
eg. All the birds can not fly.
Not all the birds can fly. 不是所有的鸟都会飞。
1. 部分否定
eg. All the birds can not fly. 并非所有的鸟都会飞。
None of the birds can fly. 所有的鸟都不会飞。
代词或副词如all, both,every,everybody, every day, everyone, everything, everywhere等与not搭配使用时，表示部分否定，意思为“并非都是"等。
eg. All is not gold that glitters. 发光的并非都是金子。= Not all is gold that glitters.
2. 全部否定
英语中常用not, none, nobody, nothing, nowhere, neither, never等表示全部否定的概念。
eg. Nothing in the world is difficult for one who sets his mind to it. 世上无难事，只怕有心人。
eg. W: Daddy, I 've decided to give up science and go to business school.
M: Well, it is your choice as long as pay your own way, but I should warn you that not everyone with a business degree will make a successful manager.
Q: What do we learn from the conversation?
A. The man doesn't have money for his daughter's graduate studies.
B. The man doesn't think his daughter will get a business degree.
C. The man insists that his daughter should pursue her studies in science.
D. The man advises his daughter to think carefully before making her decision.
双重否定
1.在阅读当中出现的频率更高一些。在一个句子中出现两个否定词：not, never, hardly, scarcely, rarely, seldom, few, little, none等，双重否定表示肯定的概念。
eg. No one can command others who cannot command himself.
A perpson can command others who command himself. 正人先正己。
eg. Without the ability to think critically, to defend their ideas and understand the ideas of others, they can not fully participate in our democracy.
如果没有能力进行批判性思维，维护自己的观点，并理解他人的观点，他们就不能充分的参与我们的民主政治中来。
2.形式否定，意义肯定
eg. A man can never have too many ties. 一个男人可以拥有很多的领带。
A woman can never have too many dresses. 一个女人拥有再多的衣服也不为过。
eg. We can hardly praise his achievement too much. 对他的成就我们无论怎样赞扬也不过分。
eg. A mother can never be patient enough with her child. 一个母亲对她的孩子再怎
么耐心也不为过。
A teacher can never be strict enough with his students. 一个老师对他的学生再怎么严格也不为过。
这种形式主要运用于阅读当中。
3. 形式肯定，意义否定
①more A than B 意思为“是A 不是B ；与其说是B ，不如说是A”
eg. The book seems to be more a dictionary than a grammar. 这本书看起来与其说是一本语法书，不如说是一本词典。
He is more a composer than a singer. 与其说他是一个歌唱家不如说他是一个创作者。
② anything but 意思为“一点都不是，根本不是，绝对不是”
eg. I am anything but a teacher. 我一定不是一个老师。
eg. I will do anything but that. 我决不干那件事。
③ no more .... than与 not more ....than
no more ...than意为“两者都不....”
eg. This book is no more interesting than thay one. 这本书和那本书一样特别没趣。
not more....than 意为“两者都肯定，前者不如后者”
eg. This book is not more interesting than that one. 这本书不如那本书有趣。
eg. This boy is not more honest than that one. 这两男孩都很诚实，前面的男孩不如后面的男孩诚实。
This boy is no more honest than that one. 这两个男孩都不诚实。
④ no more than与 not more than
no more than 强调“少”，译作“只有、不过、仅仅”
eg. He said no more than we had expected. 他只是说了我们所预料的而已。
eg. Though they think it takes no more than three days to fulfill the mission, I believe it takes not less than six days. 虽然他们认为完成这任务只需三天，但我却认为至少需要六天。
not more than 是客观叙述，意为“不超过”。
eg. He has not more than five dollars on him. 他身上带的钱不超过五美元。
eg. He is not more than 10 years old. 他最多不超过10岁。
实例练习
1．
M: Wow, that's a big assignment we've got for the psychology class. W: Well , it's not as bad as it looks. It isn't due until Thursday morning. Q: What does the women mean?。
A. The assignment looks easy but actually it's quite difficult.
B. The assighment is too difficult for them to complete on time. C. They cannot finish the assighment until Thursday. D.They have plenty of time to work on the assighment.
2．
M: I ran into our friend Mark yesterday on the street and he said he hadn't heard from you for two months.
- 考试辅导
