Ⅰ.否定結構。否定結構除了在助動詞、情態動詞，be和have后面加not之外，還有許多不含not的否定結構。很多考生因為不理解他們的真正涵義，在寫作時就不會正確使用，若能正確使用他們，文章會顯得生動活潑，增加寫作的閃光點。下面我們就來看看:
1． 含有否定意義的詞匯和短語
以下列舉的詞和詞組本身就具有否定的含義，因此無需用否定詞。
介詞against, beyond, but, except, without,...
形容詞和動詞absent, deny, differ, different, fail, free, ignore, miss, refuse, reluctant, lack,
短語keep...from, protect...from, prevent...from, let alone, at a loss, in vain, instead of, out
of the question, rather than, too...to, by no means, anything but,...
我們看以下例句：
1） Women fail to get the equal rights in some countries.
   在一些國家里婦女沒有得到平等的權利。
2） This is by no means the best way to solve the problem of energy crisis.
   這不是解決能源危機的最好的辦法。
3） We should protect trees from being destroyed.
   我們應保護樹木，不讓它們受破壞。
4） In old China we could not make a nail, let alone(make) machines.
   在舊中國，我們連一個釘子都造不了，更不用說制造機器了。
2． 含有半否定意義的詞語
barely, hardly, few, little, rarely, scarcely, seldom, not all, not everyone, not everything,...具有半否定的意義。例句：
1） We could hardly see any fresh vegetables in winter on market several years ago.
   幾年前在冬天市場上很難見到新鮮蔬菜。
2） These young people know little about how to choose good books to read.
   這些年輕人幾乎不知道怎樣挑選優秀的書籍來讀。
3． 不含否定意義的否定結構
有些詞和詞組形式上是否定結構，但其含義是肯定的，比如：cannot but, can't help,
no sooner...than, not...until, in no time, none other than, nothing but,等等。例句：
1） We can't but face the reality.
   我們只有面對現實。
2） These old buildings will be replaced by modern apartment buildings in no time.
   這些舊建筑將很快為現代化的公寓所代替。
4． 否定結構的倒裝語序
我們有時為了強調而把否定詞和詞組放在句首，這時句子結構應倒裝。例如：
1） On no account should we follow blindly.我們決不應當盲從。
2） No where has the world ever seen such great enthusiasm for learning as in our
   country.沒有任何其他地方有我國這樣高的學習熱情。
Ⅱ、 含有it的結構
考生病句：
1. As is known to all of us that science and technology play an important role in the
   development of society.
2. It is known to us, practice makes perfect.
正確表達：
1. It is known to all of us that science and technology play an important role in the
   development of society. (或:As is known to all of us, science...)
2. It is known to us that practice makes perfect. (或:As is known to us, practice...)
評議與分析：
很顯 然，兩個考生混淆了it和as的用法。如果用it作形式主語，后面的主語從句必須由that引起；如果用 as，則后面不能用that，因為as是關系代詞，代表practice makes perfect。
It 在英語中是個相當活躍的代詞，在寫作中我們常要使用它。以下幾種用法應熟練掌握，并能靈 活運用。
1．作形式主語
It is necessary for us to master a foreign language skillfully. It makes difference whether
we could purify the air or not.
2.作形式賓語
We find it rather difficult to prevent people from doing that. Modern science has made it
possible for babies to grow healthily and for people to live longer.
3.引導強調句
It is only by this way that we can achieve success. It was then that people began to realize
the importance of controlling population.
從語法結構來看，上述的句子都不難，或者可以說是考生相當熟悉的。然而在寫作考試中，多數考生缺乏運用自己已掌握的句式的意識，而以自己頭腦中拼湊的中式英語取而代之。其實，只要能恰當地運用上述的任何一個句式，考生的作文就會出現閃光點，就會取得比較好的成績。