Thread Closed
Outside of just saying that a character Said a Witty Thing, the answer would be No, if you're not capable of constructing something that is witty.
This assumes some sort of absolute wittiness, but the same thing is true for all facets of a character, like it or not.
You could debate whether or not things are truly witty, or truly smart, or whatever else, of course. But whatever you personally define as witty / smart / whatever trait you want, is only achievable if you, too, are capable of constructing that behind the keyboard. You can always state narratively that your character says Something if you can't make them say that yourself, however, though writing-wise, this will fall flat for most people even if the character would be true to themselves regardless.
An easy way to see this would be to play a character that is a mathematician, as they work in a field which does have a sort of absolute correctness in most cases. If you can't do the math that your character is supposed to be doing, then it's very clear that you can't "play" a mathematician. Sure, you could get people that are mathematicians to help you out, or vaguely say that they are Doing Math, but if you are incapable of grasping or understanding that facet of a character, then you won't be able to play them to the fullest extent of their characterization.
So, individual reflections on what is or isn't reflective of various traits on a specific level aside, this is the answer to your question.
This assumes some sort of absolute wittiness, but the same thing is true for all facets of a character, like it or not.
You could debate whether or not things are truly witty, or truly smart, or whatever else, of course. But whatever you personally define as witty / smart / whatever trait you want, is only achievable if you, too, are capable of constructing that behind the keyboard. You can always state narratively that your character says Something if you can't make them say that yourself, however, though writing-wise, this will fall flat for most people even if the character would be true to themselves regardless.
An easy way to see this would be to play a character that is a mathematician, as they work in a field which does have a sort of absolute correctness in most cases. If you can't do the math that your character is supposed to be doing, then it's very clear that you can't "play" a mathematician. Sure, you could get people that are mathematicians to help you out, or vaguely say that they are Doing Math, but if you are incapable of grasping or understanding that facet of a character, then you won't be able to play them to the fullest extent of their characterization.
So, individual reflections on what is or isn't reflective of various traits on a specific level aside, this is the answer to your question.