when writing a dialogue using speech marks do you have to put new line each person speaking?

You don't have to put a new line for each person speaking in dialogue, but it's generally recommended. Here's why:

Benefits of New Lines:

* Clarity: It makes the dialogue easier to read and understand who is speaking.

* Visual Flow: It breaks up the text, making it more visually appealing.

* Emphasis: It can be used to emphasize a particular speaker's words.

* Pace and Rhythm: It can control the pace and rhythm of the dialogue.

When New Lines Aren't Necessary:

* Short Exchanges: For very brief back-and-forth exchanges, one line can be used.

* Dramatic Effect: Sometimes, omitting new lines can create a sense of urgency, tension, or rapid-fire dialogue.

Example:

With new lines:

> "Hello," said John.

> "Hi," replied Mary.

Without new lines:

> "Hello," said John. "Hi," replied Mary.

Ultimately, the choice is yours! Use your best judgment to determine what works best for your story and your intended effect.