What's the difference between "grace" and "gracefulness"?
Despite the fact that "grace" can be a verb, what else differences do they have?

I read this sentence from somewhere else: What happened to your gracefulness?!
I know for sure this sentence is correct.
But can "grace" be substituted for "graceful" in this sentence ?

Thanks in advance.Sorry. It should be "gracefulness" instead of "graceful".

Question

What's the difference between "grace" and "gracefulness"?
Despite the fact that "grace" can be a verb, what else differences do they have?

I read this sentence from somewhere else: What happened to your gracefulness?!
I know for sure this sentence is correct.
But can "grace" be substituted for "graceful" in this sentence ?

Thanks in advance.Sorry. It should be "gracefulness" instead of "graceful".

Answer

grace is a pretty complex concept. 
for example "to show grace to" is similar to "to be kind to".

graceful is to move and act with grace. i.e. to move fluidly and dignified.

so grace is the action of grace.

gracefulness is the being the embodiment of somebody who exhibs grace.

He moves with a lot of grace.
He moves gracefully.
He is the embodiment of gracefulness.