句子多样性（sentencevariety）是雅思写作的一个考察重点，与雅思写作评分标准中的“语法多样性与准确性”（Grammatical Range and Accuracy）密切相关。因此，句型的丰富变化也是雅思考生们必学的功课，尤其对有志冲击雅思7分及以上高分的同学来说，更是一大加分点。

而作为英语中非常重要的一个语法现象，现在分词（-ing）和过去分词（-ed）是提升句式多样性的一大利器，但同时也是学习中的一个难点和易错点。从现在起，Eileen老师会分四次重点分析写作中常见的现在分词和过去分词用法，助你活学活用，为考生加分！

1. 现在分词 vs. 定语从句

在写作中，现在分词短语常常可以用来替换句中的定语从句，使句子结构更精简，形成多样化的句式。

现在分词既可修饰人，也可修饰物，被修饰的成分可以是主语、宾语或其他名词性质的成分。如：

(a) Thenumber of international students coming to western countries increased greatlyin recent years. 近几年，赴西方国家的留学生数量大幅增加。

→ The number of international students who came to western countries increased greatly in recent years.

(b) Thisis a tourist book giving information about the dos and don'ts one should knowwhen they travel to South East Asia. 这是一本介绍东南亚旅游须知的导游书。

→ This is a tourist book that gives information about the dos anddon'ts one should know when they travel to South East Asia.

(c) Anew stadium coveringan area of 10 square kilometres will be built in the north of thecity. 城市北侧将兴建一座占地10平方千米的体育场。

→ A new stadium which covers an area of 10 square kilometreswill be built in the north of the city.

(d) Therewere over 1000 students studying fashion designing in this college. 这所大学里有一千多名学习时装设计的学生。

→ There were over 1000 students who are studying fashion designing in thiscollege.

(e) Onecan hardly imagine the number of bacteria growing insidea refrigerator. 人们很难想象冰箱里滋生的细菌的数量。

→ One can hardly imagine the number of bacteria that are growing inside arefrigerator.

【注】现在分词作定语成分时，它所对应的定语从句的谓语可以是一个一般时态的动词，如句（a）（b）（c），也可以是一个进行时态的动词，如句（e）（f）。

2. 现在分词 vs. 状语从句

现在分词的另一重要用法是充当状语，通常用以表示原因或时间。

1) 表示原因：相当于一个原因状语从句

(f) Staying up latelast night, he felt asleep in the meeting this morning. 由于昨晚熬夜，他今天上午开会时睡着了。

→ As hestayed up late last night, he felt asleep in themeeting this morning.

(g) Thegovernment planned to build another metro line across the city, hoping to reduce the traffic congestion during the rush hour. 为了缓解高峰时段的交通拥堵，政府计划再建一条穿过市区的地铁线。

→ The government planned to buildanother metro line across the city, because they hope to reduce the trafficcongestion during the rush hour.

2) 表示时间：相当于一个时间状语从句

(h) While constructing the new residential area, the workers found anold tomb from the Ming Dynasty. 在建新住宅区时，工人们发现了一个明朝古墓。

→ Whilethey were constructing the new residential area, theworkers found an old tomb from the Ming Dynasty.

【注】现在分词作状语，表示“在做某事的过程中，发生了某事或做某事。”这时前面保留when，while等连词。

(i) Knowing thegovernment's new environment protection policy, many high-techcompanies started developing products that are environmental-friendly. 了解了政府新出台的环保政策后，许多高科技公司开始开发更环保的产品。

→ Whenthey know the government's new environment protection policy, many high-tech companies started developing products that areenvironmental-friendly.

【注】现在分词作状语，表示“一个动作一发生，另一个动作随即发生。”