除了一般的“某个人做某件事情”和“…have…”句型，常见的人化主语的句型还有很受考生偏爱的几个情态动词，如can, may, should等。一般建议前两个改成It is likely /possible to do/ that….；后一个改成It is necessary/ imperative/ highly expected/ suggested that sth. be done.的句式，请看下面的例示：

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.

归纳起来说，议论文中我们要积极避免“某个人”做主语，尽量用不定式、动名词或者一个从句做主语，谓语动词用评价性的动词充当，这样就可以由记叙文性质的“过程性句式”顺利转化成更符合议论文文风的客观评价性的句式。

二 被动句式的使用

在比较正式的新闻、商务、法律等英语文体中，被动句式因为其更突出客观性的宾语或者事实被广为使用。雅思的图表分析和议论文都是比较正式的文体，所以我们也应该注意多用被动句式。尤其是在以下两个方面：

1.主语不确定

Someone murdered the millionaire last night.→

The millionaire was murdered last night.

2. 主语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.