Punctuation

Rule: The apostrophe’s most common use is making a word possessive. If the word already ends in an s and it’s singular or is a person’s name, you also add an ‘s. If the word ends in an s and is plural, just add an apostrophe.

Example: The patient's results, the doctor's opinion, Charles's diagnosis, the managers' decision

Rule: Periods and commas go within quotation marks. Question marks within quotes follow logic—if the question mark is part of the quotation, it goes within. If you’re asking a question that ends with a quote, it goes outside the quote.

Example: Maria said, “I love coffee.” Who was it that said, “Coffee is bad”?

Rule: Full sentences get a period, phrases do not.

Rule: When writing a list, use the serial comma (also known as the Oxford comma). Otherwise, use common sense.

Rule: Only use space after the colon, not before the character. The text after a colon is written with a capital letter, whenever it consists of an independent sentence, direct speech, or a headline.

Example: Changes in circadian rhythms: adolescents are more alert at night

Rule: The hyphen (-) is used to join words to indicate that they have a combined meaning e.g., compound words or that they are linked in the grammar of a sentence or to indicate the division of a word at the end of a line.

Rule: A suspended hyphen may be used when a single base word is used with separate, consecutive, hyphenated words which are connected by ‘and’, ‘or’, or ‘to’.

Example: nineteenth-century and twentieth-century may be written as nineteenth- and twentieth-century

Rule: Use hyphens for combination of letters and names. Every word is written with small letters after a hyphen.

Example: Anti-acid, anti-fungal, cell-to-cell, IL-12+ (Exception: T cells, B cells)

Defined spelling: 43-year-old, 6-day-old

Rule: The em dash (–) or long dash is used to mark off information or ideas that are not essential to an understanding of the rest of the sentence. But it’s also used to show a break in a sentence where a comma, semicolon, or colon would be traditionally used. There are no blank spaces.

Example: The Microsoft share–as in the previous year–has grown significantly. The Microsoft share has grown significantly–but this is no surprise.

Example interval values: A–Z, Page 37–39

Rule: Use in place of a pair of dashes or commas around a non-defining phrase (one which adds extra information, a translation, dates, an explanation or a definition). Do not use square brackets, even in case of brackets in brackets.

Rule: Use an ellipsis to show that some text is missing, usually from a quotation or in a question – do not surround it with spaces.

Example: He said that…

1. ...he will go to the doctor.

2. ...he will go home.