EMT pls: I'm wondering... 15 year old??

Hi everyone,

Let's speak about English grammar.

I know an adjective can never be in the plural.
I know a noun can be considered as an adjective -grammatically speaking- such as in "I'll paint the 100 table legs by tonight" and never takes the "s" of the plural (there're a few exceptions).

What about "The 15 years old girl"?
The 15 years old girl? The 15 year old girl?

In my knowledge:

• "the 15 years old girl" is correct
  
• "the 15-year-old girl" is correct
  
• "the 15 year old girl" is acceptable

Do you confirm? Thank you!

Hi Gérard, hi everyone
I would choose the 15-year-old girl"what about you, native speakers ?

Hi Muriel,

#1 and #2 are definitely correct.

I'm wondering about #3 though we can see this format very often... accepted or correct?

Hi Muriel and Gérard,

No, I'm not dead !
Just been very very busy with too much work.

And the winner is ... Muriel !
The best answer is "the 15 year old girl"
I would say that the hyphens in "the 15-year-old girl" are optional !

Not so good is "the 15 years old girl" ... sorry Gérard !

In English, we say the girl is 15 years old, the baby is 12 months old
BUT
then we say the 15 year old girl, the 12 month old baby

krystynaD a écrit:... In English, we say the girl is 15 years old, the baby is 12 months old
BUT
then we say the 15 year old girl, the 12 month old baby

Very interesting, thanks Krystyna!

Bonjour Krystyna, Muriel, bonjour à tous,

krystynaD a écrit:... The best answer is "the 15 year old girl"
I would say that the hyphens in "the 15-year-old girl" are optional !

Not so good is "the 15 years old girl" ... sorry Gérard !...

A few days ago, I was atttending a meeting; as it was not that interesting, I read the National Geographic and noted the expressions I met.

- a two-foot-long sea cucumber
- under a rainy-season sky
- midstream-island dwellers
- solar-powered school boat
- long-term lessons
- primary school enrollment

They tend to put hyphens...

Hi Gérard,

Ah yes, but I still stand by my hypothesis that hyphens are optional !