Is there any difference between "to know" and "to know about" when they refer to an abstract thing? Examples:
- I know (about) this difficulty/problem.
- I know (about) Engineering.
In the first sentence, it seems to me that "to know" expresses that the speaker experienced the problem/difficulty before while "to know about" only expresses that the speaker has heard or read about it. In the second sentence, it seems to me that "to know" expresses a deeper knowledge than "to know about". Are those impressions correct?
This is NOT a duplicate of ""Know about" vs. "know of"", which focus only on "to know about" and "to know of".