Apostrophes are used to indicate possession, contractions, and missing letters. When the same symbol is used to indicate a quote-within-a-quote, it is referred to as a single quotation mark rather than an apostrophe. In order to determine when to use apostrophes, it is important to refer to the basic rules and their exceptions.
Possessive apostrophes are used with nouns, or persons, places, and things. In the case of singular nouns, the possessive is usually formed by adding ‘s. Consider these examples.
Grandmother’s shawl Spain’s seaports a chocolate bar’s ingredients
Plural nouns that do not end in s form a possessive by adding ‘s such as with the following apostrophes examples.
women’s golf shoes men’s track event children’s soccer
Apostrophes after s occurs with plural nouns that end in s. Possession is shown with apostrophes after s, such as with these examples.
sisters’ apartment City Parks’ renovations books’ covers
There are some situations where apostrophes rules dictate that possessive apostrophes should not be used. This is the case with possessive pronouns such as its, his, hers, yours, and theirs. This is also the case, in general, with plural numbers such as 1930s fashion, or for standard abbreviations such as NASAs launch dates.
Contractions provide another situation of when to use apostrophes. These are primarily used with informal speech and writing. Apostrophes are used to replace missing letters, such as with the following apostrophes examples.
I am → I’m they are→ they’re we are→ we’re
There are other situations where apostrophes are used to replace missing letters. This is the case with slang, buzz words, and neologisms, or lop-offs. The apostrophes rules for these situations include well-known examples such as the following.
Computer→’puter magazine→’zine neighborhood→’hood
While formal writing dictates including this form of punctuation, since these abbreviated words have become so prevalent, many writers leave them out.
In the area of creative writing, poets often use this device to manipulate syllable counts with metered poetry. It is also used to create or represent regional dialects in fiction and other styles of writing.
Rules for these situations include the following examples.
Darkening → dark’ning until→’til water→wate’
There are quite a few resources available online. Sites such as Purdue’s The Owl (available at http://owl.english.purdue.edu/), and handbooks such as The Brief New Century Handbook with Exercises by Christine A. Hult and Thomas N. Huckin, and Diana Hacker’s The Bedford Handbook, are considered to be reputable publications.