My teenager shuts himself in his room and answers my questions in a word or two. What should I do?

Silence and a closed door are usually not a rejection of you, but a teenager's need for his own space. At this age a child is building his identity, so a barrage of questioning only makes him close up even more. Change your approach: ask fewer questions and offer more calm presence. Spend time together with no agenda, such as driving, cooking or walking, because teenagers talk more easily side by side, not face to face. Accept short answers without complaining, and let conversation flow at his pace. When he begins to open up, listen without judging so that he knows your heart is always open to him. See educating the family.