Use dialogue to show your reader the nature of the character. Their words should reveal, admit, incite, accuse, lie, inform, manipulate, misdirect, hint, order, encourage, and so on, all in the service of advancing the story. Dialogue reveal character and lays down dramatic questions to move the story forward; if it does not serve these purposes, it can probably be deleted.
Related
Citations
George, Elizabeth. Mastering the Process: From Idea to Novel. Viking, 2020.
