Question

Hello,
I'd like to know if the following sentence is correct.
"Children breathing rate is twice as much as adults'."

Answer 1

Looks wrong to me.

Answer 2

I think it should be *Children breathing rate is twice more than adults.*

Answer 3

You have a breathing rate of something. That is a posessive. On top of that, the something is plural. Therefore you need the plural possessive.
http://www.meredith.edu/grammar/plural.htm

Answer 4

Thank you for your answer, but I still can't get it.
What I mean is that breathing rate of children is the double of the rate of adults breathing rate. Would it be right :to say, " children's breathing rate is twice as much as adults' " ?

Answer 5

Yes.
"Children's breathing rate is twice as much as adults'."
"A child's breathing rate is twice as much as an adult's."
"Children's breathing rate is twice that of adults'."
And so on.

Answer 6

Thank you so much!