Semi-colon

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.

Here shown after a dotted circle symbol:

◌;

Knowing how to use semi-colons correctly is the main purpose of university education.

History

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. 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.

Usage

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.

Constraints

1. 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.
2. 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.

Usage

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.”