除了一般的“某個人做某件事情”和“…h(huán)ave…”句型，常見的人化主語的句型還有很受考生偏愛的幾個情態(tài)動詞，如can, may, should等。一般建議前兩個改成It is likely /possible to do/ that….；后一個改成It is necessary/ imperative/ highly expected/ suggested that sth. be done.的句式，請看下面的例示：

We can go anywhere we like with our bicycle. →

It is possible for us to go anywhere we like with our bicycle.

To curb global warming, our government should promulgate new laws to govern the felling of trees.→

To curb global warming, it is imperative that our government promulgate new laws to govern the felling of trees.

歸納起來說，議論文中我們要積極避免“某個人”做主語，盡量用不定式、動名詞或者一個從句做主語，謂語動詞用評價性的動詞充當，這樣就可以由記敘文性質(zhì)的“過程性句式”順利轉(zhuǎn)化成更符合議論文文風的客觀評價性的句式。

二 被動句式的使用

在比較正式的新聞、商務(wù)、法律等英語文體中，被動句式因為其更突出客觀性的賓語或者事實被廣為使用。雅思的圖表分析和議論文都是比較正式的文體，所以我們也應(yīng)該注意多用被動句式。尤其是在以下兩個方面：

1.主語不確定

Someone murdered the millionaire last night.→

The millionaire was murdered last night.

2. 主語是泛指很多人或者大部分人

To improve the air quality, we should reduce the use of private cars. →

To improve the air quality, the use of private cars should be reduced.

Most people think that we can get a large share of benefit in the sales campaign.→

It is widely believed that we can get a large share of benefit in the sales campaign.