We all have our own style of punctuation, but the general rule is to use just enough for clarity. It helps to keep sentences short, so that punctuation is kept to a minimum. Besides, long, involved sentences can confuse the reader, even if they are grammatically correct.
The most straightforward approach to punctuation is to read a sentence aloud to yourself and add punctuation to express the pauses you would make if speaking.
A full stop normally shows that a sentence has ended. If the subject changes or the sentence is getting long or complex, use a full stop and begin another sentence.
Use a full stop rather than a question mark to end an indirect question, eg:
She asked when the proof would be ready.
Use commas as separators where a short pause is needed - perhaps where you would pause briefly if speaking. Try not to use more than two or three commas in a sentence: split it up in other ways instead, or start a new sentence.
Pairs of commas are used to show where something extra has been put in, eg:
The guest speaker, Sarah Jones, kept the audience spellbound for a full hour.
Use a comma to mark off thousands in numbers of one thousand or more when shown in figures, eg:
The semi-colon serves two useful purposes. It can take the place of a full stop to link what would otherwise be two closely related sentences, eg:
We have studied this problem for several days; more work is necessary.
It can also be used to separate long or possibly ambiguous items in a series, especially when the items already include commas, eg:
The elected officers are John Smith, President; Sarah Jones, Vice President; Edward Morris, Secretary; and Susan Pope, Treasurer.
The bullet point does the same job as a semi-colon would in a continuous list of text. Bulleted sentences therefore don't need semi-colons after them. An exception is lists in formal legal texts, where meaning can be made certain by more elaborate punctuation.
There are three ways to use a colon:
to introduce a list (as in the statement above)
to say `here comes some important news', eg In the end everyone was surprised: the couple moved to Australia
to separate two closely related but contrasting statements, eg Empowerment: a risk worth taking.
Use an apostrophe to show that a letter is missing, eg:
It's no concern of mine.
Be careful not to confuse it's (a contraction of it is) with the possessive its, which does not contain an apostrophe. For example:
It's a matter of concern to the school and its pupils.
Use an apostrophe to show possession, eg:
the people's friend
the three inspectors' reports.
Be careful where you put the apostrophe when there is more than one possessor. Compare, for example, `the applicant's forms' with `the applicants' forms'. In the first phrase, there is one applicant who has two or more forms. In the second, there is more than one applicant and each has one or more forms.
Remember, when showing possession by a person whose name ends with an `s', that you don't need to add an additional `s', eg:
John Jones' memorandum.
It is not necessary to use an apostrophe to show the plural of abbreviations, eg PCs, P60s, 1990s.
Hyphens link words that together form one adjective, eg:
a six-year-old child
a four-day wait.
There are no spaces either side of the hyphen. Don't use a hyphen in a phrase including an adverb (a word often ending in -ly that describes a verb), eg `rapidly growing economy'.
Clarity is the key. The following two examples illustrate the potential confusion when an adverb is taken for an adjective and vice versa:
`an ill, educated man' and `an ill-educated man'
`a long-lost ruler' means that the ruler has been lost for a long time, whereas `a long lost ruler' means that the ruler is both long and lost.
Use a hyphen to indicate a range of numbers, dates and page numbers, eg:
Hyphens are also used to distinguish a less common pronunciation or meaning of a word from its more customary usage, eg:
a recreation hall
re-creation of a scene
to recover from an illness
re-cover the sofa.
When a hyphenated word splits between the end of one line and the start of the next, you should keep the whole word together. You can do this in Word by inserting a non-breaking hyphen. Click where you want to insert the hyphen and press Control + Shift + Enter.
Dashes are useful in emails and informal notes to mark an abrupt change in thought or grammatical construction in the middle of a sentence - they help to break up sentences like natural speech. Single dashes are also useful in formal documents - for example, in the previous sentence - while a pair of dashes can help to cordon off an aside or explanation that you wish to highlight (as in this sentence). Used in pairs, they are thus an alternative to brackets or pairs of commas.
There are two types of dashes, en-dashes (the width of the letter n) and em-dashes (the width of the letter m). The en-dash is a little neater than the em-dash but, whichever style you decide to use, make sure you use it consistently throughout your document.