A ten-year-old boy

[Rachel Adams]

Hello.

Sometimes I see "A ten-year-old boy" written as "A 10 years old boy."
Which is more common use? Can I use "ten-year-olds" in plural?

 

[Yankee]

Hello.

Sometimes I see "A ten-year-old boy" written as "A 10 years old boy."
Which is more common use? "ten-year-old" Can I use "ten-year-olds" in plural? Yes if, for example, you might say, "He is the brightest among all the ten-year-olds" .

Y.

 

[GoesStation]

Sometimes I see "A ten-year-old boy" written as "A 10 years old boy."

Not by a native speaker.

Which is more commonly used? Can I use "ten-year-olds" in plural?

The correct one. Yes, if you're talking about more than one kid. Not here though.