Recently one of my friends told me that there is distinct difference between 'know of something' and 'know about something' expressions. 'know of' is used when you have personal experience with wha...
"Know about" vs. "know of" - English Language & Usage Stack Exchange
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.
to know vs to know about - English Language & Usage Stack Exchange
Why do you think that He doesn't know him from his schooldays means that he does know him? It would only have that sense if you added something like In fact, he first met him at university.
Why? Because you've just told them! It's like when saying "Did you know strawberries aren't berries, but bananas are?", I didn't know if you'd already known about that factoid prior to my "question", but at the time I say it onward, I know you know it because I've just told you. Therefore, it'd be reasonable to use the past tense with "did".
Should I use "did you know" or "do you know" to introduce a fact?
In my understanding, ' as we know it ' usually follows a noun phrase and means like The building as we know it = the version/condition of the building we know now. First, I'm not sure about its grammar. Is the 'as' a conjunction? Is it correct to think that 'it' changes to 'them'? E.g., the buildings as we know them Second, a question about its use. Is it possible to use when the preceding ...