The grammar item in this unit focuses on verb-ed and verb-ing, both of which are also called participles. You will review the functions of verb-ed and verb-ing in different situations. You are expected to apply what you learn to practice by fulfilling some written tasks.

Step 2: Explanation:

1. 分词的构成

分词分为现在分词和过去分词。现在分词构成为V+ing, 过去分词构成为V+ed。分词也有一般式、过去式、完成式及主动和被动等各种形式。

2. 现在分词和过去分词的区别

1) 在时态上，现在分词表示正在进行，而过去分词表示已经完成。

Developing countries 发展中国家The developed countries 发达国家

　 Boiling water 沸腾的水 Boiled water 开水

2) 在语态上，现在分词表示主动，而过去分词表示被动。

The oppressing class 压迫阶级 The oppressed class 被压迫阶级

Burning fire 燃烧的火焰 Burned skin 烧伤的皮肤

3. 分词的时态与语态

1) 一般式（主动、被动）

分词的一般式的主动式所表示的动作与谓语动词表示的动作同时发生，或在谓语动词表示的动作之前发生。其被动式表示这个动作正在发生或与谓语动作同时发生，主要作定语、状语或宾补。

　　E.g. When I entered the room, I found him reading. 当我进入房间时，我发现他在读书。

I found the flowers watered. 我发现花已浇过了。

The building being repaired is a hospital. 正在修建的建筑物是一家医院。

He found the matter being talked everywhere. 他发现到处都在谈论这件事。

Being surrounded, the enemy were forced to put down their guns.