Find the mistake: When conflicts happen (A)we sit together and discuss (B). We need understand (C) each other (D) better.
Knowledge: Verb “need”
With “need” as a verb, we have the structure “to need to do sth”: what to do
With “need” as a modal verb, we have “need + Vinf”: what to do
Understanding => to understand or understand
Translated: When conflicts arise, we sit down and discuss. We need to understand each other better.