句子構成的成分共分為九種：主語，謂語，賓語，表語，定語，狀語，補語，同位語和插入語。

一、主語：句子的核心主體，通常位于謂語動詞之前，表明一個句子是誰或何種情況所發出執行或是承受的。在雅思寫作中常做主語的有名詞、代詞、主語從句、V-ing 、To do五種。

1名詞：Computers are now being widely used in almost all fields.

2代詞：We are now living in an information-explosion era.

3主語從句：Whether sports stars should earn a high salary is still discussed heatedly.

4V-ing: Surfing the Internet offers a new way for people to relax themselves.

5To do: To protect the environment is everybody’s business.

二、謂語：描述或闡述主語的情況，由動詞來充當，常位于主語之后。

1表狀態用系動詞：As I see it, movie stars’ earning a high salary is unfair and unjustified.

2表動作用及物或不及物動詞：The Internet has revolutionized people’s way of life. Taste differs.

3表擁有：人或物時用：have has 無生命的東西：there be

People have different views on this question.

There is no absolute agreement on this question.

4情態動詞＋動詞原形：

In this way, teachers can never be replaced by computers.

三、賓語：及物動詞或介詞所指向的對象。在雅思寫作中常做賓語的有名詞、賓語從句、復合結構、V-ing 、To do五種。

1名詞作賓語：International tourism promotes the economic development.

2賓語從句作賓語：Some people hold that air travel should be restricted.

3復合結構：The advanced medical technology has made it possible for people to live longer than ever possible before.

4 V-ing: Nobody can avoid being influenced by media.

5 To do: Some people want to work for a big company while others choose to work for a small one.