Use of colons and semicolons

The colon

The colon is commonly used when introducing a list

(一般的にコロンはリストを紹介する時に使われる。)

A list in a sentence

Garcia’s Mexican restaurant has three specialties: tacos, enchiladas, and chile rellenos.

Do not, however, use a colon when the listed items are incorporated into the flow of the sentence.

(しかしながら、リスト化されたアイテムが文脈に取り込まれるとき、コロンは使わないでください。)

Correct: The specialties of Garcia's Mexican restaurant are tacos, enchiladas, and chile rellenos.

Incorrect: The specialties of Garcia's Mexican restaurant are: tacos, enchiladas, and chile rellenos.

A bulleted or vertical list

(箇条書きリストか縦書きリスト)

The colon is used to introduce a bullet list, also called a vertical list, when the clause preceding the list is an independent clause. In other words, the vertical list can stand alone as a sentence.

(リストの前の節が独立節である場合、箇条書きリスト?また、縦書きリストと呼ばれている?を紹介するためにコロンは使われます。言い換えると、縦書きリストは文として独立することができます。)

Email writing has become the most common form of business communication over the past ten years:

・         It is used for communicating simple messages.

・         It is used to give short reports and summaries of meetings.

・         It often takes the place of the memo pad, telephone and postal mail.

Notice that each item in the list ends with a period. This is because the items are complete sentences.

(リストのそれぞれの文がピリオドで終わっています。これはそれぞれの文が完全な文であることを意味しています。)

Colons are also used to introduce bullet lists when the expressions, as follows or the following are used.

(コロンは「follows」もしくは「the following」を使い、表現を用いた箇条書きリストを紹介するときに使われます。)

Disadvantages do exist in email, and it is important to be aware of them so that you do not embarrass yourself or your company. They are as follows:

1. Once an email is sent, you have limited or no chance to retrieve it.

2. Emails can be offensive.

3. Email is frequently overused.

Colons are not used when the clause introducing the list is not an independent clause.

(リストを紹介している節が独立節でないときコロンは使われません。)

For email to be useful to you and your company, the writing must be clear. Your writing must include a clear organization, such as

1. a clear beginning in the form of a single sentence that tells the main point of your message,

2. a middle section that explains your main point,

3. an ending that summarizes your main point and explanation

The colon is used between independent clauses when the second clause explains or illustrates the first clause.

(コロンは第2節が第１節を説明する、または例示するときに独立節の間で使われます。)

In this manner, the colon operates in much the same way as the semicolon. As with the semicolon, do not capitalize the first word after the colon unless the word is ordinarily capitalized.

(この様に、コロンはセミコロンと全く同じように働きます。セミコロンと同様に、元々大文字の単語でない限りコロンの後の最初の単語は大文字にしないでください。)

I have very little time to finish the report: it’s due in two weeks.

Note: In this sentence, the second clause is explaining why the person has little time to finish the report.

(注：この文では、なぜレポートを終える時間がほとんどないかについて第2節が説明しています。)

All three of the new products go on sale this month: The thermostat sale begins next week. The faucets sale will start the second week of the month. Finally, the shower heads will go on sale in the last week of the month.

Note: When two or more sentences follow a colon, capitalize the first word following the colon.

(注：二つ以上の文がコロンに続く場合、コロンの後の最初の単語は大文字にしてください。)

The colon can be used for emphasis

(コロンは強調を目的としても使われる)

The colon can be used to emphasize a phrase or single word at the end of a sentence.

(コロンは文の最後のフレーズ、もしくは単語を強調するために使うこともできます。)

After three weeks of experimenting, the researchers finally reached a conclusion: it is not possible.

I visited clients in three countries and five different cities in ten days: namely, I’m exhausted.

The colon in other uses of punctuation

(コロンの句読点としての別の用法)

The colon is used after a greeting in a formal letter:

(コロンはフォーマルな手紙のあいさつの後に使われる。)

・         Dear Mr. Johnson:

・         To Whom It May Concern:

・         Dear Sir or Madam:

・         Dear Ms. Standoffish:

Note: The colon is not used in an email message greeting. Instead, use a comma.

(注：コロンはEメールでのあいさつでは使われません。代わりとしてコンマを使用します。)

The colon is used in telling time:

(コロンは時間を表記する際に使われます。)

・         12:30 AM

・         3:35 PM

Use a colon for subtitles:

(コロンを字幕や副題のために使う。)

・         Edward Jones: A look into his soul

・         Images: A pictorial look at the people of Okinawa

Use a colon to introduce long quotations:

(長い引用を紹介する際にコロンを使う。)

The famous ad man, David Ogilvy, once commented on the use of grammar rules when writing copy for ads:

I don't know the rules of grammar... If you're trying to persuade people to do something, or buy something, it seems to me you should use their language, the language they use every day, the language in which they think. We try to write in the vernacular.」

If a quotation contains two or more sentences, many writers and editors introduce it with a colon rather than a comma.

(多くの作家と編集者は引用が二つ以上の文を含む場合、コンマよりもむしろコロンで引用文を紹介します。)

My mother always told me: “Don’t drink. Don’t take drugs. Don’t gamble.”

The semicolon 

Use a semicolon between independent clauses when a coordinating conjunction is omitted

(等位接続詞が省略されるとき、独立節の間でセミコロンを使います。)

Note: The use of the semicolon is not common. It is better to use the conjunctions “and” or “but” if you want to join two short independent clauses

(注：セミコロンの使用は、一般的でありません。二つの短い独立節を連結させたい場合は「and」、もしくは「but」などの接続詞を使用することをおすすめします。)

Most commonly, the semicolon is used between two independent clauses (i.e., clauses that could stand alone as separate sentences) when a coordinating conjunction (for, and, nor, but, or, yet, so) is omitted.

(一般的には、2つの独立節?すなわち、別々の文として独立することのできる節?の間で、等位接続詞「なぜならば」「そして」「また」「しかし」「または」「それでも」「だから」が省略された時にセミコロンが使われます。)

The most senior employees will sit at the front table; the first-year employees will sit at the table behind the senior employees.

Note: The example above could be recast with the conjunction and, in which case a comma, rather than a semicolon, would be required.

(注：上の例は、接続詞「and」を代用でき、この場合はセミコロンではなくコンマを入れる必要があります。)

The most senior employees will sit at the front table, and the first-year employees will sit at the table behind the senior employees.

Note: Technically, the semicolon could be replaced with a period, since each independent clause is a complete sentence. The semicolon, however, emphasizes the connection between the two clauses. The use of a conjunction like “and” or “but” is the most common way of connecting two independent clauses.

(注：技術的に、各々の独立節が完全な文である時、セミコロンはピリオドと置き換えることができます。しかし、セミコロンは2つの節の間のつながりを強調します。接続詞の用法である、「そして」や「でも」は2つの独立節をつなぐ方法として最も一般的な方法です。)

Use a semicolon between independent clauses linked by a transitional expression

(移行表現によって結ばれた独立節の間でセミコロンを使います。)

The semicolon is also used between two independent clauses linked by a transitional expression (e.g., accordingly, consequently, for example, nevertheless, so, thus).

(セミコロンは移行表現「例えば」「それに応じて」「従って」「たとえば」「それでも」「だから」「このように」によって結ばれる2つの独立節の間でも使われます。)

The use of solar energy has been doubling every two years for the past five years; consequently, the world will have more than enough energy in two more doublings.

The use of MRIs has expanded greatly in the past few years; thus, scientists are better able to understand how the brain works.

Note: It is more common to use a period to separate the two independent clauses. Therefore, a semicolon is seldom used.

(注：2つの独立節を切り離すためにピリオドを使うことがより一般的です。したがって、セミコロンはあまり使われません。)

The semicolon can be used in lists with internal commas

(セミコロンは内部コンマのリストの中で使われる。)

Note: In this case, the semicolon is necessary.

(注：このケースではセミコロンが必須です。)

The semicolon can also be used in lists with internal commas. In this usage, the semicolon acts as a sort of super-comma. In other words, to avoid confusion, the semicolon separates the main components of the list.

(セミコロンは内部コンマのリストの中で使われます。この使用法では、セミコロンは一種のスーパーコンマの働きをします。言い換えると、混乱を避けるために、セミコロンはリストの主要構成部分を切り離します。)

The new office will be divided into sections by level; reception, meeting rooms, and auditorium on the first floor; research, development, and 3d printing on the second floor; and employee offices, mid-level management offices, and senior-level management on the third floor.

We have people coming from all over the US, such as San Diego, California, New York, New York, Miami, Florida, Sioux Falls, Idaho, and Portland, Oregon.

Note: All of the commas make it difficult to know what city is matched with its corresponding state.

(注：全てがコンマであるとどの都市がその該当する州とマッチするかわかりづらくなります。)

We have people coming from all over the US, such as San Diego, California; New York, New York; Miami, Florida; Sioux Falls, Idaho; and Portland, Oregon.

Note: In this example, the state names have colons after them, making it easier to see the cities that belong to them.

(注：この例では、州の名前の後にコロンがある場合、それらの州に属する都市を見分けることを容易にします。)