A semi-colon or ; is a punctuation mark which separates major sentence elements. A semi-colon can be used between two closely-related independent clauses provided they are not already joined by a coordinating conjunction. semi-colons can also be used in place of commas to separate the items in a list, particularly when the elements of that list contain commas.
Knowing how to use semi-colons correctly is the main purpose of university education.
The first printed semi-colon was the work of the Italian printer Aldus Manutius the Elder in 1494; Manutius established the practice of using the semi-colon to separate words of opposed meaning and to allow a rapid change in direction in connecting interdependent statements.Template:Sfn Ben Jonson was the first notable English writer to use the semi-colon systematically. The modern uses of the semi-colon relate either to the listing of items or to the linking of related clauses.
Although terminal marks (i.e. full stops, exclamation marks, and question marks) mark the end of a sentence, the comma, semi-colon and colon are normally sentence-internal, making them secondary boundary marks. The semi-colon falls between terminal marks and the comma; its strength is equal to that of the colon.
- When a semi-colon marks the left boundary of a constituent (e.g., the beginning of a clause or a phrase), the right boundary is marked by punctuation of equal or greater strength.Template:Citation needed
- When two or more semi-colons are used within a single construction, all constituents are at the same level, unlike commas, which can separate, for example, subordinate clauses from main clauses.Template:Citation needed
semi-colons are followed by a lower case letter, unless that letter would ordinarily be capitalized mid-sentence (e.g., the word "I", acronyms/initialisms, or proper nouns). Modern style guides recommend no space before them and one space after. They also typically recommend placing semi-colons outside ending quotation marks, although this was not always the case. For example, the first edition of The Chicago Manual of Style (1906) recommended placing the semi-colon inside ending quotation marks.
Applications of the semi-colon in English include:
- Between items in a series or listing containing internal punctuation, especially parenthetic commas, where the semi-colons function as serial commas:
- The people present were Jamie, a man from New Zealand; John, the milkman's son; and George, a gaunt kind of man with no friends.
- Several fast food restaurants can be found within the following cities: London, England; Paris, France; Dublin, Ireland; Madrid, Spain.
- Here are three examples of familiar sequences: one, two, and three; a, b, and c; first, second, and third.
- (Fig. 8; see also plates in Harley 1941, 1950; Schwab 1947).
- Between closely related independent clauses not conjoined with a coordinating conjunction, when the two clauses are balanced, opposed or contradictory:
- My wife would like tea; I would prefer coffee.
- I went to the basketball court; I was told it was closed for cleaning.
- I told Kate she's running for the hills; I wonder if she knew I was joking.
- Either clause may include commas; this is especially common when parallel wording is omitted from the second:
- Ted has two dogs; Sam, one.
- When a comma replaces a period (full stop) in a quotation, or when a quotation otherwise links two independent sentences:
- "I have no use for this," he said; "you are welcome to it."
- "Is this your book?" she asked; "I found it on the floor."
- "I have no use for this," he said. "You are welcome to it."
- "Is this your book?" she asked. "I found it on the floor."