Which spelling you use largely depends upon what side of the Atlantic you’re on. And if on the British side of the pond, then it’s only slightly more complicated.
In American English, judgment (no e) is the preferred spelling. This is because back in the 1820s, Noah Webster, when he wrote the first American dictionary, decided to simplify the spelling of a number of words. Today, The AP Stylebook and American Heritage and Merriam-Webster’s dictionaries among others echo this spelling.
In British English, both spellings are used, though they have the same meaning. Judgment is used in official court documents while judgement prevails elsewhere, however.
A simple memory trick: “Add the e if in England” (which many Americans often incorrectly call the entire United Kingdom…but that’s another topic for later).
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My name is Rob Bignell. I’m an affordable, professional editor who runs Inventing Reality Editing Service, which meets the manuscript needs of writers both new and published. I also offer a variety of self-publishing services. During the past decade, I’ve helped more than 300 novelists and nonfiction authors obtain their publishing dreams at reasonable prices. I’m also the author of the 7 Minutes a Day… writing guidebooks, four nonfiction hiking guidebook series, and the literary novel Windmill. Several of my short stories in the literary and science fiction genres also have been published.