Every semester, I begin my classes with a few questions. I ask my students what an "essay" is. I do this in pretty much all my classes, since I think writing's really important in all my classes, so I'm used to a variety of answers. And I learn something from these answers.
Some graduate students tend to think I'm asking a trick question to make them feel stupid or something. Some graduate students look blank. Some answer confidently.
I learn which students have learned to distrust professors. I learn which students haven't thought reflectively about the work they've done in the past, and which students have picked up what their writing teachers probably wanted them to learn.
In my literature classes, most students answer with some confidence. A few look blank, and a few get nervous about forgetting what they were supposed to learn in their first year writing class.
I learn which students are willing to answer even an obvious question, which probably aren't going to be active learners in my class, and which may not remember much from their first year classes (for whatever reason).
In my first year writing classes, most students look confused. A few offer tentative answers.
I learn that they've been told to write "essays" for 4+ years, but that no one's ever really taught them what an essay is. What the heck? Can I just make a request to EVERY teacher who assigns anything called an "essay" that s/he take five minutes in class to look up the word together, talk about what an essay is, and what the expectations for the assignment are?
On one level, doing my little exercise teaches students about me, too. I hope they learn that I'm going to try to be explicit in my expectations, that I'm going to try to answer questions, that they can hold me to the same standards I hold them to as far as defining terms, providing examples, giving reasons for what I think or expect.
I hope the graduate students learn that I don't ask trick questions. Real questions are plenty hard, and I ask lots of those.
If I can teach students those things, then they'll let me teach them other things a lot more easily because I'll have begun to earn their trust in my role as their professor. After that, of course, I have to do my best to live up to their trust.