How to properly punctuate ‘et al.’

One of the most common abbreviation mistakes that new writers make, especially when penning academic papers, is the Latin phrase et al. Part of the problem is that we don’t know Latin; another part is that neither do our computer spell checkers.

Et al. means “and others”. Et is Latin for “and” while alii is Latin for “others”. In modern English, we don’t abbreviate et but we do abbreviate alii to al. Because of this, the correct way to spell et al. is with one period after the l, as in: Boston et al. found that hiking just 20 minutes a day can change a person’s mood for the better.

Sometimes writers will forgo the period after the last l, but for academic papers written in APA style, it is required. A few spell check programs will flag this as an error, however, so watch for it.


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.