What do you do if you don't know or can't answer a student's question? Like, "Do you know why there's an inversion when you use embedded questions?" What you absolutely do NOT do is make up an answer to cover for the fact that you don't know or you're not sure. That's just being disrespectful to the student and to English teachers everywhere!
Tell them the truth! Tell them you're not sure. Tell them you don't know. Then tell them that the first thing you're going to do is find out the answer to their question as best as humanly possible, and then go and find out! Present the answer in the next class, or send them an e-mail with a clear and understandable explanation. On the other hand, if you thought the answer you gave them was correct, but you discover you were, in fact, wrong, let your students be the first to know! Don't double down on your position. If they find out the truth somewhere else, you lose credibility, big-time!
Do you know what happens when you're honest with them? It impresses your students tremendously (I wanted to say that it impresses the hell out of them, but I thought that was a bit vulgar). It proves that you're truly interested in helping them learn and it shows them you're passionate about what you do. Do you know what that's worth to a student and to you as a teacher? It's priceless! And the knowledge you gain by looking up the answer will stay with you for a long time.
Oh, by the way, do you the answer to why we use inversions in embedded questions? Be honest and let me know!