Is failure to understand someone's dialect a result of an inability to communicate or an inability to comprehend?

Both.

Communication is about both the sending and the receiving.

When we learn to speak, we emulate the sounds we hear most frequently. In order to understand a different dialect, we need to retune our ears to broaden the sounds we interpret to include different ones that mean the same thing. I seldom have difficulty understanding different dialects, but primarily because I am not afraid to ask people to say something again or speak more slowly, indicating clearly that *I* am having trouble understanding them (not that *they* are having trouble speaking).

Inability to comprehend.

Failure to understand someone's dialect is a result of an inability to comprehend


inabilty to communicate is if you don't even try.

I think it is simply an inability to comprehend the dialect.

Failure to comprehend.

Neither. It is simply the failure to understand someone's dialect.

People communicate fine, the failure lies with the person trying to understand.

An American passing through an Australian airport pulled out his cigarette lighter when the customs officer said "see you later" to him. The way an Australian says "later" sounds like the way an American says "lighter".

To an American, an Australian saying "lighter" would sound like he is saying "loida"

Let me quote what Burt Reynolds said in the movie "Smokey and the Bandit":

"When you tell somebody something, it depends on what part of the country you're standing on as to how dumb you are."

Heck Yeah!

So obviously you've seen the movie and remember that line.

I think most people do not listen, I am guilty of that. I think most people do not examine context of literature. This is unfortunate.

Inability to comprehend

I think it's some of both, but it's more of a failure to comprehend.