To format dialogue by two characters as dual dialogue (i.e., simultaneously spoken), simply select/place the insertion point on the first character element and select Format > Make Dual Dialogue.
BOB I am saying this.
ALICE I am saying something else.
By placing the cursor on "BOB" and selecting Dual Dialogue, it will change things to:
BOB ALICE I am saying this. I am saying something else.
Tags: dual dialogue