I've had to train literally hundreds of people over the various jobs I've had and it causes me to over explain in almost every conversation.

I got two tricks to figure out how much someone knows about a topic and encourage them to ask questions rather than lie just to avoid being a little uncomfortable.

First, I look for them to use vocabulary that I haven't already mentioned or if they seem to understand something just by using a couple words.

Second, I ask them to explain something early in the conversation to make it easier to ask if they don't understand something later. It's usually really simple, but it really does work to lower communication barriers.

I like to think it makes us feel more like equals trading expertise, rather than like I'm some authority talking down to them.

I hope this helps anyone