When characters take action, they are trying to change the world in some way. We see the results of their actions by the way the world reacts to their actions.
For example:
Shorty stalked over, his hands up, assuming the hood boxer pose. “I don’t want no trouble,” Miles said, his body still firing tiny rockets through his veins. Shorty didn’t respond, just continued to set up his stance, then reset it. He finally threw a jab. Miles bobbed. He threw another. Miles leaned back, moved from side to side, his arms down, letting Shorty know he didn’t want to fight.
This snippet shows a simple set of actions and reactions as Shorty repeatedly tries to hit Miles, and Miles repeatedly dodges.
Here are some examples that use the same pattern.
Sasha wandered down the alleyway, and threw open the garbage bin lid. A black shape leapt out in a blur. Sasha stumbled back with a start, letting out a small yelp. The cat yowled back, before darting past. She jumped out of the way to let it go, dropping the garbage bag she was carrying. The noise caused the cat to pause at the end of the alley, before darting off into the night.
Cassie came to the counter holding the glass of lemonade. “That’s three dollars,” she told the customer. The customer brought out their wallet and produced their bank card. Cassie shook her head and pointed to the “$5 card minimum” sign. The customer sighed and began to root around in their pockets, until finally they pulled out a few coins and handed them to Cassie. She counted them out, put them in the cashbox, then handed over the glass of lemonade.