Currently, I'm tutoring a 9th grader in biology. After fielding some questions about cell division, he asks me, "Are you good at math?" I say, "Yes." we then work on a bit of geometry. He then asks me, "Are you good at English?" I told him that I am, and that's one of the reasons his mother picked me. I'm reasonably capable and knowledgeable in many areas.
But the truth is a bit more complicated. I'm not a good tutor just because I know a lot of things about a lot of subjects. Knowledge helps, but it's not the whole story.
Parents appreciate my subject area competence. But they appreciate...