Wondering when you should hyphenate the words “year old”? The answer is pretty simple: whenever the words are used as an adjective (as in “the 16-year-old driver”), they should be connected with a hyphen.
Read on for more on when and how to hyphenate “year old,” as well as when the hyphen isn’t necessary.
When to Hyphenate Year Old
“Year old” should be hyphenated when it modifies a noun that follows it. That is, when the phrase is describing the age of a person, place, or thing, and it precedes that noun in a sentence, then it should be written as year-old.
In such cases, a hyphen should also connect year old to the number that precedes it (for example, “20-year-old girl”).
Note that these rules apply regardless of whether words or numerals are used to convey the age.
Examples
- The 100-year-old building did not survive last year’s storm.
- The three-year-old was reunited with his mother.
- My 25-year-old sister is getting married this spring.
- Her 2-year-old cousin is sleeping.
- His 95-year-old grandmother is coming for Thanksgiving.
- The 12-year-old boy wanted to run away from home.
When the age itself is a noun, year old still needs to be hyphenated.
For example:
- The 10-year-old was very loud.
- For being a 5-year-old, she’s very independent.
When Not to Hyphenate Year Old
Year old should not be hyphenated when it comes after the noun it modifies (as in, “She is 12 years old”).
Examples
- This building is 150 years old.
- I was 20 years old when I moved abroad.
- My father just turned 63 years old.
- This wine is 4 years old.
- The villages is hundreds of years old.
To Hyphenate or Not to Hyphenate?
That is the question. We’ve got the answers in our guide on how to use hyphens, as well as more on em dashes and en dashes.
Proper punctuation is key for clear, effective, and professional writing, so make sure you understand these basic rules!
Did you find this post helpful? Let us know in the comments below!
If you enjoyed this post, then you might also like:
- How to Use a Hyphen
- How to Use Dashes: Your Guide to the Em Dash, En Dash, and Hyphen
- The En Dash: When and How to Use It
- When to Write Out Numbers: What Chicago, APA, and MLA Say About Numerals
As a blog writer for TCK Publishing, Kaelyn loves crafting fun and helpful content for writers, readers, and creative minds alike. She has a degree in International Affairs with a minor in Italian Studies, but her true passion has always been writing. Working remotely allows her to do even more of the things she loves, like traveling, cooking, and spending time with her family.
Thanks for this comprehensive explanation. I found it very helpful.
Now 59-years-old, he is in rude health.
Is this sentence correct?
Excellent explanation of the hyphenation issue. However, I caught a typo in one of the examples:
The villages is hundreds of years old.
I hope you don’t mind my pointing that out.
No
One example I’m not seeing here is whether to hyphenate usage such as “Only the three-year-old laughed.” Their is no trailing noun, such as “boy,” so the term “three-year-old” seems to function like a pronoun. My intuition says it should be hyphenated but now I’m not sure. Please clarify.
Hi Peter, thanks for your question! Your intuition’s right: it should be hyphenated (“the three-year-old”). I think that’s because the noun is kind of implied, even if it’s not specific (whether it’s boy/girl/child/dog/etc.)
I am 5 years old or I am five year old ..
How about this — describing someone at an age they were in the past. Is it:
“my then-three-year-old”
or
“my then three-year-old”
Hi Lindsey, I’m pretty sure it should be then-three-year-old, since then modifies the rest of it :)
Why is a hyphen needed between the age and year? I can see the reason to hyphenate “year-old”.
@Peter Straton
I dunno why you consider it a “pronoun” .
Hi, please could you clarify where the following sentence would need to be hyphenated ‘thank you for referring this 35 year old lady who….’ and ‘this 35 year old lady was referred….’, i am presently being pulled up for putting hyphens in, would be so grateful if you could let me know what is the correct way of typing….. This 35-year-old, this 35 year-old or no hyphens?
Many thanks
Hi Sally, in both sentences it should be “35-year-old”
Oh my, what have you gotten yourself in to, answering specific questions? Wow you are dedicated!
I try my best :) always happy to help
I have a question, if I’m writing “A century and a half ago the volcano erupted” would it need hyphens? I am having trouble figuring out this rule. Thanks
Hey Toni! Compound adjectives that talk about spans of time don’t need to be hyphenated :)
This article is very helpful , however I am still a bit confused. I am trying to enter a writing contest and I would like to spell out “thirty-five year old” it is the beginning of my sentence and I cannot put the word “the” in front of it due to word count constraints. Should it be thirty-five year old, thirty-five-year-old or thirty-five year-old? The sentence would be “Thirty-five year old [character name here] was the kind of guy that my parents…”
Hey Cierra! For your sentence, the “thirty five year old” should be hyphenated since it comes before the noun it modifies :)
Hi It’s helpful to me thkx a lot
Hey Mrym! I’m glad you found it helpful :)
Hi. What if you are writing … “ since he was two years old ….
Great article. Very helpful!
Is there a way to subscribe to your posts? Sorry if it’s obvious and I’m just not seeing it.
Hey John! We don’t have that as of now but you can always visit the blog at anytime :)
I just read a comment that says “..your grammar is of a 5 year old” and thought to myself that it should have been written as “Your grammar is of a five-year-old.” I WAS pretty confident about that, but came here to check and find myself thoroughly confused! I am laughing at myself now and would truly appreciate your help. Thank you so much!
Hey Eileen! In this case, the year old isn’t hyphenated because the noun (grammar) it modifies appears before it. Hope this helps!
Just wondering if it’s correct usage when someone writes “they were dating for two-and-a-half-years”
I see this with the half added in there, which to me looks really clunky, but it’s technically correct?
I do think it’s correct to hyphenate the half considering that “two-and-a-half-years” is considered as one whole entity in the sentence.
Thanks. Great explanation!
thanks Marjorie, glad you found the post helpful!
Would it be “I just turned sixty-three and a half”
“I just turned sixty-three-and-a-half”
“I just turned sixty three and a half”
Hi Brendan, the first option, “sixty-three and a half” would be correct
Hi
I always thought that I should pronounce it like :
100 year old
And
When more than a 100:
Like:
108 years old
Can you explain when we use it with or without an S please
Thanks!
Hi Moe, thanks for your comment! It depends on if you’re just stating how old someone is, or using their age as a modifier. For example, you would use the S to say “She is 100 years old” or “She is 108 years old.” However, you would drop the S and add a hyphen to say: “The 100-year-old woman…” or “The 108-year-old woman…”. Hope that helps!
Hi Kaelyn and thanks in advance! Am I correct in using hypens this way in the following sentence:
I pay $500 a month for gas- or oil-related expenses.
Hi Cynthia, yes, that is correct!
Thank you!
Struggling with this sentence:
My father was 8 or 9 years old when…
or
My father was eight or nine years old when…
or
My father was an 8- or 9-year-old when…
or
??? Help????
Hi Kay, regarding the first two, the difference is in whether you write the numbers our or not. That would depend on your style guide (most would recommend spelling it out), but both are technically correct from a grammar/punctuation standpoint. The third option is also correct since you added “an”. Again, you’ll have to decide if you want to spell out or keep the numerals, but the hyphens are used correctly.
This is a perplexing exception to normal English grammar rules. I had a student ask me just now whether to write, “My sister is one year old,” or, “My sister is one-year old,” because a quiz she was taking said the latter choice was the correct answer. Normally, my procedure is to break modifiers down individually and attach them to the noun to demonstrate when a hyphen is needed, e.g., “2-car garage” vs “2 car garage.” You wouldn’t say “2 garage,” and you wouldn’t say “car garage.” It only makes sense if you combine 2 and car to create a uniquely descriptive modifier. Following that rule, you wouldn’t say “one sister” or “old sister” because these both lose the intended meaning; neither would you say she is one-year old. You just don’t. I can’t find a rationale for this in the standard rules, but I’m 100% certain that this is how it’s done. I hate not having a coherent principle to point to.
Hi RD, yes it’s definitely an interesting rule. One similar example I can compare it to is saying “the man is six feet tall” vs. “the six-foot-tall man”
Which is the proper way to write this according to the rules?
My seventeen year old self was wondering …
My seventeen-year-old self was wondering…
“My seventeen-year-old self” :)
Should the sentence start off with, 13 year old girl is the number of my idol, Rent. OR. Thirteen year old girl is the number of my idol, Rent. I think it should be spelled out but in the publication, it showed 13 year old girl as the beginning sentence. Do you have any recommendation on hyphen placement?
Hi Ronnie, generally when you start a sentence with a number, it should be spelled out, and hyphenated like this: Thirteen-year-old girl
I remember my college English professor telling me that all years of age other than one should be written in the plural, such as two-years-old. Should I ever make the age plural?
Hi Kerry, if you’re describing a person (for example, “the two-year-old boy”) it should be hyphenated but year should stay singular. If you just want to say “the boy is two years old,” then there should be no hyphen, but years should be plural.
In editing a brochure today, I came across “30-40 year old,” which I thought would be “30-to-40-year-old.” Is this correct (my AP Style Book is at the office, haha). Thank you.
Hi Sam! First, sorry for not responding sooner, I just saw your comment. I can’t actually find a solid rule for this, but I do see it written the first way (30-40 year old) pretty often, and that’s definitely not correct. To make it simpler, I would do: “30- to 40-year-olds,” so like your idea, but you can drop the hyphen after “to.” Or, I think you could also use an en dash for the range (30–40-year-olds). Hope that helps! :)
Was just editing something with: Young adult,
20-24 years old group. And, am based on the above, changing to follow the proposed, i.e. “young adult, 20- to 24-year-olds group” ! So glad I found this thread; thanks again!
You’re very welcome Lara, we’re glad you found the post helpful! :)
Hello Kaelyn, please help.
Music for the 5-year-olds or Music for the 5-year-old’s
Thanks
Thanks. Very helpful in deed.
Glad you found it helpful! :)
Hi, I’d love confirmation of whether to hyphenate “then-” when talking about someone’s previous age, e.g., “the then-15-year-old…”.
I can’t tell if there’s meant to be a hyphen there or not. Thanks in advance!
Hi Katie, thanks for your question! The Chicago Manual doesn’t address the use of “then” as an adjective, but Merriam-Webster accepts either form (though seems to prefer without the hyphen). I hope this helps!
Thank you.Your publication helped me to have better understanding of this subject.
You’re welcome Agada, glad you found it helfpul!