Tell your child they can ask you three questions about anything — your day, your childhood, what you are thinking.
Answer properly and at length. Then ask them the same question back and listen the same way.
Do this at a fixed moment, like the walk home or the end of dinner, so it becomes something expected rather than an event.
Asking about another person's experience, and then hearing the same interest returned, is how conversation stops being a series of announcements. Children who are asked real questions and given real answers learn that other people have insides worth enquiring about.