Should you use an apostrophe when you write about “a good night’s sleep”? Yes.
You’ve probably heard a teacher say that an apostrophe signifies ownership. That statement is correct, but it’s only part of the apostrophe story.
Apostrophes signify “of” ideas. Mary’s car means “car of Mary.” Dennis’ dog means “dog of Dennis.” Three weeks’ pay means “pay of three weeks.” And so on.
The apostrophe in “a good night’s sleep” means “sleep of a night.”
Time expressions often use apostrophes. A day’s pay means “pay of a day.” Two weeks’ vacation means “vacation of two weeks.” A moment’s delay means “delay of a moment.”
“Before the s or after the s?” If you take a minute to look at the example, you’ll have the answer: Spell the word (day, days, week, weeks, night, nights, moment, moments, Dennis, Mary) and put the apostrophe after the last letter.
Here are some examples:
a day’s delay
two days’ delay
a week’s pay
two weeks’ pay
a good night’s sleep
two nights’ dreams
a moment’s delay
several moments’ anxiety
For more practice with apostrophes, click here. You can watch a short PowerPoint about apostrophes here.
Thanks, Jean! I see one error – in second to last example, it should be “a moment’s delay”, not “a moments’ delay”. (And, yes, I know, I put the comma and period in the wrong place – at least for American English. It’s intentional; I don’t like the correct system and I’m advocating for a change through my own action.) The incorrect example is actually correctly written earlier in the article.
Good grief! That post has been up there for ages, and nobody noticed. (Of course I should have caught it – I’m blushing!) John – thanks so much for your brain and your sharp eyes!
Dear Jean,
Thank you for your post.
I have a question about this example: several moments’ anxiety
Shouldn’t it be? Several anxiety’s moments? As in “Several moments of anxiety?”
Cheers.
Hi, Eduardo – great questions!
Languages aren’t logical. You make a great point, but English simply doesn’t work that way. Ultimately a language is a social tool. When the majority of people adopt a certain language practice, it becomes the correct version, even if we don’t like it or it doesn’t make sense.
Most English-speaking people would phrase your expression this way: “anxiety of several moments.” Then it becomes “several moments’ anxiety.”
Similarly we would say “worry of many years.” Then it becomes “many years’ worry.”