Dialogue tags, those phases before or after dialogue that indicate who has spoken, can help the reader navigate a scene. Still, they are not necessary for every single line of dialogue. Exchanges between characters can be written so that some lines of dialogue are easily attributed without a tag. In Jennifer Egan’s “Found Objects” in A Visit From the Goon Squad, Sasha is on a first date with Alex. On their way out of the hotel where they have dinner, a woman follows them. She’s desperately looking for her wallet, which Sasha has swiped from her purse earlier in the evening. Alex has this exchange with the woman:

Alex turns to the woman. “Where did this happen?” “In the ladies’ room. I think.”
“Who else was there?”
“No one.”
“It was empty?”
“There might have been someone, but I didn’t see her.”
Alex swung around to Sasha. “You were just in the bathroom,” he said. “Did you see anyone?”

Egan uses only one dialogue tag and the exchange is clear. Each new paragraph indicates a different speaker, and that is enough for the reader to easily follow this back and forth. Egan also uses action in the narrative to indicate the speaker. The exchange starts with Alex turning to the woman and the reader knows that the dialogue immediately following is his.