Problem: Continue the following story.

Jason had to ask Randy for help checking their car's differential because 
Here's how I want to continue it: Jason never works on their own car.

Problem: Continue the following story.

Since Nelson was assertive at work and Donald was not, 
Here's how I want to continue it: Donald did not make a lot of sales with their clients.

Problem: Continue the following story.

Derrick left the room after becoming annoyed by Samuel's constant complaints about his hemorrhoids, because 
Here's how I want to continue it:
Samuel was whiny.