導(dǎo)讀：上期我們向大家介紹了靈活使用“There be”結(jié)構(gòu)和準(zhǔn)確使用比較結(jié)構(gòu)。本期繼續(xù)向大家寫好句子的另外兩種辦法。

三、表達(dá)原因結(jié)構(gòu)
【考生病句】
1．The real reason to our failure is not far to seek.
2．The reason for this is because he wants to earn plenty of money without
working hard.
【正確表達(dá)】
1．The real reason for our failure is not far to seek.
2．The reason for this is that he wants to earn plenty of money without working
hard.
【點(diǎn)評】以上兩個病句分別引自四級考試考生作文。從遣詞造句上看，這兩位考生具有一定寫作能力，not far to seek, plenty of money以及without working hard均運(yùn)用正確、恰當(dāng)。不足之處是第一位考生不知道reason不與to搭配而應(yīng)接介詞for，第二位考生犯的錯誤比較典型，就是用because引起表語從句，because這個詞不能引起表語從句，應(yīng)改用that才正確。
掌握好表達(dá)原因結(jié)構(gòu)是十分重要，幾乎所有寫作涉及到寫原因。四級考試寫作文體基本上是議論文，而議論文基本模式是擺事實(shí)、講道理，而講道理就是說明原因。英語中用來表達(dá)原因的詞和詞組有很多，例如：as , because, since, seeing that, considering that, now that等。
1. Now that we have seen these great achievements with our own eyes, we feel more
proud than ever of our country.
2. Since we live near the sea, we enjoy a healthy climate.
3. Pollution is still a serious problem, not that we don't have the ability to solve it, but that
some people have not realized the consequences of the problem.
除了上述例句外，英語中還有很多或易或難表達(dá)原因結(jié)構(gòu)。我們在進(jìn)行寫作訓(xùn)練時候，不能滿足于一知半解，要講究書面語言正確性和準(zhǔn)確性。比如，because是常用于引導(dǎo)原因從句連詞，語氣最強(qiáng)，表示直接原因，若because置于句首，后面的句子不能再用so。用as引導(dǎo)原因從句語氣較弱，所說明原因是附帶，而since表示原因暗示著是稍加分析之后才能推斷出來原因。

四、否定結(jié)構(gòu)
【考生病句】
1.Some people think we needn't to worry about fresh water.
2.Nowadays many people don't like to go to the movies, too.
【正確表達(dá)】
1.Some people think we needn't worry (或don't need to worry) about fresh water.
2.Nowadays many people don't like to go to the movies, either.
【點(diǎn)評】病句1的錯誤在于該考生混淆了need作為情態(tài)動詞和作為實(shí)義動詞的用法。need作為情態(tài)動詞時，主要用于否定句，后面動詞不帶to； need作為實(shí)義動詞時，可用于肯定句、否定句和疑問句，don't need to worry 中to worry作don't need的賓語。病句2的錯誤在于該考生混淆了too和either的區(qū)別， too, also只能用于肯定句，而either只能用于否定句。