Dialogue packaged only for the reader—without concern for the characters in the exchange—is bound to sound forced. For example, a husband says to his wife:
"I can't go to the shop after dark anymore. My brother Doug died driving that same stretch of road because it was dark out."
The wife already knows about the brother's death and the circumstances under which he died. How often are your friends and loved ones telling you obvious information about themselves as if that information were new?
Here's a revision of how that dialogue might sound in the course of natural conversation:
"I can't, not since Doug's accident."
If the brother’s death is even more recent or otherwise on the surface for this couple, his dialogue might be even more abrupt:
So how do you get the rest of that information to the reader? Narrative and suggestion. Here's an example of how it might be done:
After dinner, his wife cleared the table. He listened to the fork on the plates as she scraped food into the garbage. She wanted those papers. He knew right where he had left them—piled atop a speaker next to his office door. If only she'd mentioned it an hour earlier, when it was still dusk. He didn’t want to have this conversation. She’d tell him to try. But he had tried and all he did was sit in the parked car thinking about Doug and the snaking road along Windsor Lake. He walked to the kitchen entryway. " I can't," he said.
This passage pays attention not only to the reader's need for information but also the history of experience between these two characters.