Using the semi-colon and colon
This guide has been written to give a simple explanation of the use of the semi-colon (;) and colon (:). It explains how they can be used effectively and gives examples of their main uses.
The semi-colon represents a break within a sentence that is stronger than a comma, but less final than a full stop. It enables the writer to avoid over use of the comma and preserves the finality of the full stop. Semi-colons are used to separate items in a list and to link closely related sentences.
To separate items in a list
Use the semi-colon to separate items in a list when one or more items contain a comma. (These examples use a colon to introduce items in the list. An explanation of the use of the colon is given below.)
The speakers were: Dr Sally Meadows, Biology; Dr Fred Eliot, Animal Welfare; Ms Gerri Taylor, Sociology; and Prof. Julie Briggs, Chemistry.
The four venues will be: Middleton Hall, Manchester; Highton House, Liverpool; Marsden Hall, Leeds; and the Ashton Centre, Sheffield.
The main points in favour of the system were that it would save time for buying, accounts and on-site staff; it would be welcome by the reception staff; it would use fewer resources; and it would be compatible with earlier systems.
To link sentences which are closely related
Closely related sentences are often linked to emphasise their relationship and to vary the pace of the writing. For example:
I read the book in one evening. It was not very helpful.
One way to link these sentences is with a comma and a word such as and, or, but, nor, for, so, yet (called co-ordinating conjunctions).
I read the book in one evening, but it was not very helpful.
For variety in sentence structure, the semi-colon can be used to link closely related sentences instead of a co-ordinating conjunction and comma.
I read the book in one evening; it was not very helpful.
The semi-colon tells the reader that the second clause is closely linked to the first clause. Note how sentences joined in this way are similar in either theme or grammatical structure as shown in the example below.
Personal writing utilises the first person form; impersonal writing utilises the third person form.
He was nervous about giving the speech; he asked for water several times.
The deadline has come forward a week; everyone's help will be needed.
For use with otherwise, however, therefore…
The semi-colon can be used to link sentences which also use words such as otherwise, however, therefore, as connectors. These connectors (known as conjunctive adverbs) also include: moreover, nevertheless, thus, besides, accordingly, consequently, instead, hence.
I did not finish reading the text; instead, I watched the news.
(Notice that the connecting word instead is followed by a comma.)
The research is far from conclusive; nevertheless, it has some value in this case.
Dr Suptri argues that the research shows an increase in such occurrences; however, many experts would dispute this.
The colon acts as a pause which introduces related information. It indicates that the reader should look forward to information that follows on from the earlier statement. Some of the main ways a colon can be used are shown below.
To introduce a list
The colon can be used to introduce the items in a list.
Topics discussed will include: the structure of viruses, virus families and current concerns in virology.
Students joining the department undertake to: attend all lectures and tutorials, meet deadlines for written work and contribute to tutorials and seminars
To introduce an explanation, conclusion or amplification
The colon can also be used to introduce an explanation, conclusion or amplification of an earlier statement. The use of the colon separates and highlights the second statement, showing that it follows on from the first.
Tai chi is more than a form of physical exercise: it is meditation in movement.
After extensive research, the committee came to its conclusion: development could not take place without further funding.
The semi-colon and colon are often underused, yet their correct use can enhance the clarity of your writing. Beware of an over dependence on the comma and full stop, as this can make for ambiguous and repetitive sentence structure. Look in your writing for opportunities to use the semi-colon and colon in the ways described in this guide.