Post History
The convention is to always start a new paragraph when you change the speaker, change the place, or change the time. In this case, you're changing the speaker, so your first example is correct. In ...
Answer
#4: Attribution notice removed
Source: https://writers.stackexchange.com/a/30839 License name: CC BY-SA 3.0 License URL: https://creativecommons.org/licenses/by-sa/3.0/
#3: Attribution notice added
Source: https://writers.stackexchange.com/a/30839 License name: CC BY-SA 3.0 License URL: https://creativecommons.org/licenses/by-sa/3.0/
#2: Initial revision
The convention is to always start a new paragraph when you change the speaker, change the place, or change the time. In this case, you're changing the speaker, so your first example is correct. In the second example it's unclear who's saying the second line - it could be Jack, or it could be Jill or Julia. **EDIT** : To clarify, if Jack's response is only physical, and he doesn't say anything, you don't need to change paragraphs at all: > Jane said, "Let's chase the ball." Jack looked at her in disbelief, and she quickly added, "Or we could deflate it."