The Best Proofreading & Editing Service. Period.
World-Class Editing — 24/7
TRUSTED IN 35+ COUNTRIES
5/5
Writing about centuries and decades can be confusing. Depending on where you look, you’ll find variations — such as Sixties, ’60s, 1960’s, 1960s, and so on. But which version should you use?
If you’re writing an academic document, you likely need to talk about the current century, since “recent” research would be in the past decade or two. So would you write the twenty-first century, 21st century, 2010s, 2010’s, or 21st Century? There are a number of options, but some of those would be incorrect. (Answer: You’d want to write the “21st century,” not spell it out — which we’ll explain more below.)
Writing the proper way is important for clarity and consistency. This guide provides comprehensive guidelines on numeral and word use, capitalization, and the correct application of apostrophes and hyphens. Refer back to this whenever you need help with writing correctly for your academic documents.
In general, use lowercase when talking about things like “twenty years ago” or “ten years from now” or “last century.” However, you should capitalize when talking about an era that is a proper noun.
Do you use an “s” when talking about decades? Many writers err here. It is extremely common to use an apostrophe (e.g., 1950’s), but that is incorrect. When talking about decades, you are not talking about possession but a plurality. So do not use an apostrophe.
To begin with, know the difference between a dash, en dash, and em dash. Do not use a long punctuation mark but the shortest (a simple – rather than – or —).
In English, there is a technique to shorten words, and that same technique can be used for dates. For example, we can use an apostrophe to show that some letters are missing. Thus, if shortening a date, you can do the same. Examples are below.
For specific years, always use numerals rather than spelling out. For example, never write it out like seventeen-seventy-six. Instead that would be written as 1776.
An exception would be when a year starts a sentence. In that case, you would write out rather than using a numeral.
Correct: Twentieth-century theologians grappled with the challenges of modernity.
Incorrect: 20-century theologians grappled with the challenges of modernity.
If there’s no requirement to adhere to a particular style guide, choose a consistent format for your document.
Examples
APA/AP
Chicago/MLA
Turabian
SBL (Society of Biblical Literature)
Various style manuals have distinct approaches to handling centuries. The APA Publication Manual and the Associated Press Stylebook advise treating ordinal numbers (e.g., “first,” “second”) similarly to cardinal numbers (e.g., “one,” “two”). Following the common practice of writing numbers under 10 in words, these guides recommend spelling out ordinal numbers for centuries between one and nine (e.g., “eighth century”) and using numerals for the 10th century and beyond (e.g., “20th century”). The Chicago Manual of Style, the MLA Handbook, Turabian, and SBL generally suggest using lowercase words for centuries (e.g., “nineteenth century”).
In academic texts, centuries should be written in words for the first through ninth centuries and in numerals thereafter. Decades should be written in numerals, with descriptive names written in words. Both centuries and decades should not be capitalized unless part of a proper noun. Apostrophes should be used sparingly, mainly to indicate the omission of century numbers in decades. Hyphenate centuries and decades when used as adjectives, but not when used as nouns.
Need help with proofreading or editing? Get complimentary access to our free step-by-step manual — featuring 30 pages of expert tips!