Punctuation

Punctuation marks are signals to your readers. In speaking, we can pause, stop, or change our tone of voice. In writing, we use the following marks of punctuation to emphasize and clarify what we mean.

CAPITAL LETTERS

Capitals are used:

• at the beginning of a sentence
• when a person talks about himself (I)
• for geographical names; places, cities, countries, islands, sea, mountains, lakes, roads
• all other names; nationalities, races, people, titles, religions, months, days

FULL STOP (.)

A full stop is used:

• at the end of a sentence
• after an abbreviation. E.g. Prof. Wilson
• within an abbreviation consisting of single capitals. E.g. M.P. = Member of Parliament. In British English the full stop is often omitted here.

A full stop is not used:

• after an abbreviation ending in the same letter as the full form. E.g. Mr = Mister
• in abbreviations of well-known institutions. E.g. UNESCO, WWF

COMMA (,)

A comma is used:

• to sum up items in a list. E.g. the Sales Manager, the Secretary and I.
• to divide off a non-restrictive (= unnecessary) clause from the main sentence; the part between commas can be left out without changing the essence of the sentence. E.g. The goods, which were expensive, arrived yesterday.
• to separate an introductory word or phrase from the sentence. E.g. In fact, the Germans did not even mention interest.
• to separate sentence adverbs from the sentence. E.g. The facility manager, however, did not agree with the proposal.

COLON (:)

A colon is used:

• before a long list of items. E.g. The case contains the following materials: cotton, wool, nylon and silk
• to indicate that the writer wants to illustrate something or explain in more detail. E.g. The countries are quite different: China has a controlled economy while Japan has a free market economy
• to introduce a direct quotation. E.g. The General Manager exclaimed: 'I certainly don't agree on this proposal'

SEMICOLON (;)

A semicolon is used:

• to separate two clauses that are considered closely connected. The semicolon expresses a relation that is too weak for a comma but too strong for a full stop. E.g. Only the Special Zones are ready for slick retail operations; the rest of the country will not be ready until the next century.

DASH (- )

A dash is used:

• instead of brackets to add material to a sentence. E.g. He entered the council chamber - and his visit was totally unexpected - to announce the senators that he had taken control.
• in informal English to separate a phrase or word from the main sentence. In formal English it is better to use commas. E.g. Alexander - our Personnel Manager - introduced the idea.
• in informal English to add an after-thought or a comment. In formal English it is better to use brackets. E.g. The sky was very clear and the atmosphere strangely calm - never a good sign at this time of year.

PARENTHESES / BRACKETS (())

Parentheses are used:

• when a date is added. E.g. John Smith (1895-1960) was the founder of the enterprise.
• to indicate references. E.g. World population (see chart on page 149) will have increased to 11.6 billion by 2150
• in informal English to add extra information or an after-thought which is not essential. E.g. Ireland (so we were told) wanted to investigate the possibilities of nuclear energy.

Complete sentences never appear in brackets. When the closing bracket is at the end of the sentence, the full stop is outside the bracket.

QUESTION MARK (?)

A question mark is used:

• at the end of a direct question.
• in brackets to express doubt. (The company was established in 1845 (?) and has exported whisky ever since.)

EXCLAMATION MARK (!)

An exclamation mark is used:

• after strong exclamations or commands. E.g. Don't forget to call Mr Jones!
• after emotional remarks (anger, fear, joy, amazement, etc). E.g. What a surprise!

APOSTROPHE (')

An apostrophe is used:

• to indicate that letters or numbers have been left out. Avoid it in formal English. E.g. She's worked there since '97.
• to indicate the possessive. E.g. Joanna's secretary
• to form the plural of letters. E.g. "Omitted" is spelled with two t's.

HYPHEN (-)

A hyphen is used:

• with certain prefixes. E.g. ex-husband, self-reliant, mid-October; especially if the prefix ends with a vowel. E.g. co-ordinator, re-establish, pre-exist.
• to form a word from two or more words (a compounds). Note that not all compound are spelled with a hyphen. E.g. radio-telescope, telegraph-line, brother-in-law

QUOTATION MARKS (") AND (')

Quotation marks are used:

• to indicate direct speech. E.g. He shouted,"You're fired!"
• to indicate that somebody's exact words are quoted. E.g. Curtis Bohlen announced that "new and additional financial resources would be needed."

In both cases the quotation marks should enclose all words and punctuation of the quoted expression. Both double and single quotation marks may be used; although the British usually prefer single and Americans usually prefer double quotation marks.