Answers to Questions About Hyphens in References to Age

By Mark Nichol

The rules about references to age, and the proper use of hyphens in such references, are simple yet easily misunderstood. Here are a few explanations in response to readers’ questions about the topic.

1. Could you help me understand the correct way to write ages? For example, “My three-year-old was too young for the movie” is hyphenated, while “He is three years old” is not, or at least I don’t think it is.

Your examples are correct: Hyphenate “three-year-old” and similar phrases only when they serve as phrasal adjectives describing someone or something (or when, as in the case of the first example above, the someone or something of that age is implied). The simple phrase “three years old” merits no hyphenation, because it isn’t being combined to modify anything. Unfortunately, many people are confused by this distinction, so the phrase is often hyphenated incorrectly, and the frequently seen error perpetuates the confusion.

2. In your sentence “Write ‘fifty years old,’ for example, rather than ‘aged fifty years,’” the phrase should read “fifty years-old,” shouldn’t it?

“Fifty years old” should be styled just like that, as explained in the previous response; in reference to a fifty-year-old, hyphenate as shown whether what is fifty years old is explicit or implicit. Never hyphenate years and old while leaving the preceding number detached, and never hyphenate fifty and year without also including old in the hyphenated string of words; “fifty-year old man” refers to an old man who is fifty years, which is nonsensical. The only case in which years and old would be hyphenated is in a sentence such as “It’s a years-old tradition” — a reference to a tradition that is (many) years old.

3. “When a doctor was dictating a report, he said, ‘This is an approximately 40 50 year old woman . . . .’ It’s my job as a transcriptionist to make the doctor look good; I don’t just type verbatim. So I put, ‘This is an approximately 40- to 50-year-old woman . . . .’ ‘This is a 40-50-year-old woman . . .’ looks awful and confusing, even though that is actually what the doctor said. I could also have written, ‘This is a woman who is approximately 40 or 50 years old . . . .’”

Both of your solutions are elegant. If, however, you were required to transcribe verbatim — and I think doing so would be necessary only in a legal context — the solution would be, “This is an approximately 40-, 50-year-old woman.” The comma indicates a pause for expansion or self-correction.

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7 Responses to “Answers to Questions About Hyphens in References to Age”

  • Preciseedit

    An en dash would be helpful with the 40 to 50 problem and would show that 40 to 50 is a range. “The 40–50-year-old woman”

  • Mark Nichol


    I usually observe Chicago style, but sometimes, when I’m copying and pasting readers’ questions that include numbers or other elements styled according to AP, I don’t reconcile that style.

  • Mark Nichol


    You’re right — “three-year-old,” in isolation, is a noun, not an adjective — and yes, “a fifty-year tradition” is correct, but that is tangential to my discussion. And “This is an approximately 40-, 50-year-old woman” is a perfectly reasonable statement — and “50” is not a correction, necessarily, but more likely an addition, and because of the context of approximately, “40 or 50” is valid.

  • W Bruce Ramsay

    OK, I didn’t see the AP style book posting. But is that sacrosanct in this context. What do medical records librarians say?

  • W Bruce Ramsay

    Instead of: “40-50-year-old . . .” I agree: far too many hyphens,

    why not simply type: “forty to fifty year-old . . .”? A few extra keystokes perhaps, but not a lot of extra effort or bytes or paper.

    (In older times, of course, it could well have been: “a woman of forty to fifty years . . .” which has a certain elegance and at the same time simplicity — and no hyphens at all.)


  • Sally Bahner

    Check your style book, too. AP style says numerals should always be used with ages. Chicago spells out numerals with ages.

  • Matt Gaffney

    The writer’s explanations are correct overall; however, there’s still some ambiguity.

    First, it’s important to note that, in the first example, “three-year-old” should not be thought of as an adjective, as implied by the writer. The three adjectives yoked by the two hyphens become a noun, which noun is modified by “my,” the subject of the verb “was,” and the the beneficiary of the predicate adjective “young.”

    Second, it would be all right to write “it’s a fifty-year tradition.”

    Third, people often forget, assuming they knew, that in all writing, a hyphen connecting numbers is always read at “to.” The phrase “40-50” is read “forty to fifty.” The original writer certainly would not have been correct to write “. . . who is approximately 40 or 50 years old.” Such a clause would mean that, if the woman isn’t 40 years old, then she is 50 years old, with no reference to the intervening years. I doubt any doctor would say “40 50 year old . . . .” If those were his/her precise words, then it might be taken as a self-correction for having said 40, but meaning 50. The doctor was more likely to have said “40 to 50 year old” which, if so, should have been written “40-50-year-old . . .” and subsequently read as “forty to fifty year old . . . .”

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