Punctuation is used to mark the cadence, pauses, and tone in written English. In other words, punctuation helps us to understand when to pause between fully formed ideas when speaking, as well as organize our thoughts in writing. English punctuation marks include:

在書面英語中，標點符號用來標記韻律、停頓和語調。換言之，標點符號有助于我們理解說話時在完全形成的思想之間停頓的時間，以及在寫作中組織我們的思想。英文標點符號包括：

period, comma, question mark ? exclamation mark ! colon :semi colon ;
句號，逗號，問號？感嘆號！冒號：分號；

Beginning English learners should focus on understanding the period, comma, and question mark. Intermediate to advanced student should also learn how to use colons and semi colons, as well as an occasional exclamation mark.
初學英語的人應該把重點放在理解句號、逗號和問號上。中級到高級的學生也應該學習如何使用冒號和分號，以及偶爾的感嘆號。

This guide provides instruction on the basic rules of using a period, comma, colon, semicolon, question mark and exclamation point. Each type of punctuation is followed by an explanation and example sentences for reference purposes.
本指南介紹了使用句點、逗號、冒號、分號、問號和感嘆號的基本規則。每種標點后面都有一個解釋句和例句，以供參考。

Period
句號

Use a period to end a complete sentence. A sentence is a group of words containing a subject and predicate. In British English a period is called a "full stop".
用句號結束一個完整的句子。句子是包含主語和謂語的一組詞。在英國英語中，句號叫做“句號”。

Examples:
例子：

He went to Detroit last week./They are going to visit.
他上周去了底特律。/他們要去參觀。

Comma
逗號

There are a number of different uses for commas in English. Commas are used to:
英語中逗號有許多不同的用法。逗號用于：

Separate a list of items. This is one of the most common uses of a comma. Notice that a comma is included before the conjunction "and" which comes before the final element of a list.
將項目列表分開。這是逗號最常用的用法之一。請注意，逗號包含在列表最后一個元素之前的連詞“and”之前。

Examples:
例子：

I like reading, listening to music, taking long walks, and visiting with my friends./They would like books, magazines, DVDs, video cassettes, and other learning materials for their library.
我喜歡看書，聽音樂，散步，和朋友們一起參觀。/他們喜歡書，雜志，DVD，錄像帶和其他學習材料為他們的圖書館。

Separate phrases (clauses). This is especially true after a beginning dependent clause or a long prepositional phrase.
單獨的短語（從句）。尤其是在從句或長介詞短語之后。

Examples:
例子：

In order to qualify for your certificate, you will need to take the TOEFL exam./Although he wanted to come, he wasn't able to attend the course.
為了獲得證書，你需要參加托福考試。/盡管他想來，但他沒能參加這門課。

Separate two independent clauses that are connected by a conjunction such as 'but'.
用連詞如“but”連接的兩個獨立從句分開。

Examples:
例子：

They wanted to purchase a new car, but their financial situation would not allow it./I'd really enjoy seeing a film this evening, and I'd like to go out for a drink.
他們想買一輛新車，但他們的經濟狀況不容許。/今晚我真的很喜歡看電影，我想出去喝一杯。

Introduce a direct quote (as opposed to indirect speech i.e. He said he wanted to come ...).
介紹一個直接引語（與間接引語相反，他說他想來…）。

Examples:
例子：

The boy said, "My father is often away during the week on business trips."/His doctor replied, "If you don't stop smoking, you run the risk of a heart attack."
男孩說：“我父親經常出差在外。”/他的醫生回答說：“如果你不戒煙，你就有心臟病發作的危險。”

Separate appositives (a noun, or noun phrase) or non-defining relative clauses.
單獨的同位語（名詞或名詞短語）或不明確的關系從句。

Examples:
例子：

Bill Gates, the richest man in the world, comes from Seattle./My only sister, who is a fantastic tennis player, is in great shape.
比爾蓋茨，世界上最富有的人，來自西雅圖。/我唯一的妹妹，是一個出色的網球運動員，狀態很好。

Question Mark
問號

The question mark is used at the end of a question.
問號用在問題的結尾。

Examples:
例子：

Where do you live?/How long have they been studying?
你住在哪里？/他們學習多久了？

Exclamation Point
感嘆號

The exclamation point is used at the end of a sentence to indicate great surprise. It is also used for emphasis when making a point. Be careful not to use an exclamation point too often.
感嘆號用在句子的結尾，表示非常驚訝。它也被用來強調時，提出一點。注意不要經常使用感嘆號。

Examples:
例子：

That ride was fantastic!/I can't believe he is going to marry her!
那次旅行太棒了！/我不敢相信他會娶她！

Semicolon
分號

There are two uses for a semicolon:
分號有兩種用法：

To separate two independent clauses. One or both of the clauses are short and the ideas expressed are usually very similar.
把兩個獨立的從句分開。其中一個或兩個從句很短，表達的意思通常非常相似。

Examples:
例子：

He loves studying; he can't get enough of school./What an incredible situation; it must make you nervous.
他喜歡學習；他不能得到足夠的學校教育。/多么不可思議的情況；這一定讓你緊張。

To separate groups of words that are themselves separated by commas.
將本身由逗號分隔的詞組分開。

Examples:
例子：

I took a holiday and played golf, which I love; read a lot, which I needed to do; and slept late, which I hadn't done for quite a while./They plan to study German, for their travels; chemistry, for their work; and literature, for their own enjoyment.
我度假打高爾夫球，這是我的愛好；我讀了很多書，這是我需要做的；我睡得很晚，這是我很久沒有做過的事了。/他們計劃學習德語，旅行；化學，工作；文學，自娛自樂。

Colon
冒號

A colon can be used for two purposes:
冒號可用于兩個目的：

To provide additional details and explanation.
提供額外的細節和解釋。

Examples:
例子：

He had many reasons for joining the club: to get in shape, to make new friends, to lose some weight, and to get out of the house./She gave notice for the following reasons: bad pay, horrible hours, poor relations with colleagues, and her boss.
他加入俱樂部有許多理由：保持身材，交新朋友，減肥，離家出走。/她發出通知的理由如下：工資低，工作時間糟糕，與同事和老板關系不好。

To introduce a direct quote (a comma can also be used in this situation).
引入直接引語（在這種情況下也可以使用逗號）。

Examples:
例子：

He announced to his friends: "I'm getting married!"/She cried out: "I never want to see you again!"
他對朋友們說：“我要結婚了！”/她喊道：“我再也不想見你了！”
（來源：滬江英語，作者：Summer）