The Editor’s Manual
Free learning resource on English grammar, punctuation, usage, and style.
Capitalize names of holidays, such as “Christmas” and “Hanukkah.” Don’t capitalize adjectives like “happy” and “merry” or common nouns like the word “holidays,” unless at the start of a sentence.
Double quotes enclose text in US style, with single quotes used only for quotes within quotes. Single quotes are the default in British style, with double quotes reserved for quotes within quotes.
Use just one period, not two, after an abbreviation like “etc.” even when it appears in quotes at the end of a sentence. Don’t add another period after the closing quotation mark.
When an abbreviation like “etc.” appears in parentheses, place another period after the closing parenthesis to end the larger sentence. But if the entire sentence is enclosed in parentheses, use just one period, not two.
An acronym is an abbreviation pronounced as a single word. It is treated differently from other abbreviations (such as initialisms) in edited text.
Don’t capitalize phrases like “happy birthday” when talking about wishing someone. Feel free to capitalize them in personal greetings.
Abbreviations are acceptable in formal writing. Explain an abbreviation at first use. Avoid overuse. Avoid using them in titles and headings or to start a sentence.
The greeting is “Happy New Year,” not “Happy New Years” or “Happy New Year’s.” It contains a singular noun (“year”) and requires no apostrophe.
To form the plural of a contracted social or professional title, add “s” and move the period to the end (“Drs. Keyland and Murphy”). The plural of “Ms.” is “Mss.” or “Mses.,” and that of “Mr.” is “Messrs.”
Use an apostrophe after “s” in “Teachers’ Day.” The noun “teachers” is thought of as a plural possessive, indicated by an apostrophe after “s.”