Why did I receive a negative response from a professor when emailing about course content and prerequisites of a course I am considering taking?
There is nothing inappropriate (that anyone can see here) in the way that you've written your email. The response from the professor suggests that they're some combination of (a) incredibly time-constrained, (b) sloppy and unclear in how they communicate, and (c) a jerk.

It's possible (as user2768 suggests) that the essential &quot;offense&quot; in their eyes was to ask about things available in the online site. If so, then their first sentence was a sloppy and mostly mindless piece of aggression that doesn't really mean what it says.

The curtness, snarkiness, and level of aggression communicates that they don't like interacting with students by email, do not want to spend time on it, and want such querents to go away and not bother them.

Given the above, writing them again and asking for more time to be spent on even smaller minutiae -- like revisiting what they meant in a hastily-written throwaway email, and to spend even more time parsing the grammar of the original student email that they've already expressed contempt for handling -- is only likely to make things worse.


I suggest that you accept this line of inquiry as not useful and likely to produce only further confusion and frustration on both sides. Do not email them again on this matter. If you must email them again in the future, on some different matter, make it as brief as you possibly can (shorter than your original email), and try to pose a question that can be given a very short, clear-cut answer.
I'll say that the only thing the professor really got right there was in accurately predicting your next instinct would be that, &quot;very soon you will be writing many more official emails&quot;, and to be aggravated-in-advance by that prognostication. Resist the temptation to fully prove them right!
Also, consider asking around if this professor is good to interact with (maybe people you know or a ratings website). If their course is not required, then you may be getting a signal that they're just not a good professor.