It's quite shocking to see people like you. I wish I had a teacher like you. I can totally relate to the guy you are mentoring because I was that guy. I simply didn't get what my senior was saying. And I was afraid to ask because I would never get a clear or straight answer. I wasn't sure whether I was asking the right questions. All my curiosity bottled up but I was too afraid/shy to ask. I stopped querying people altogether, I started doing my own research. I started learning on my own. I spotted my weakness and worked on that. All the shitty times where I felt worthless built a drive to figure things on my own. I am doing okay now but I believe if seniors at my office tried to understand my foundation or where I stand with the required skills, I would have progressed faster.

First day in internship a senior hands me an ip address and a password in a piece of paper. We were working in a flask project. He said " just look at basic flask tutorial and here's the ip". I didn't know what to do with that. It took me 3 days to figure out that was an Database server login details by looking at the code he had written.

Just listen to him. Don't undermine or criticize him. Encourage and make suggestions. Make him solve problem and appreciate his efforts. Give honest feedback but gently and politely. At least that's what wish someone did for me.