Rumors have been circulating about Apple's next iPhone for quite some time. Here's what we know about the iPhone 18 so far. Recently one of my friends told me that there is distinct difference between 'know of something' and 'know about something' expressions.

Understanding the Context

'know of' is used when you have personal experience with wha... 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. Should I use "did you know" or "do you know" to introduce a fact?

Key Insights

I've only seen "did you know" in action. My logical deduction is that before the "question" (which is not much of a question because you're not asking for an answer), you wouldn't have been sure whether the listener'd known about what you're about to say or not. 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?

Final Thoughts

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 ... Possibly, "I do know that" can in fact only be used, when, you are answering the question of whether or not you know the issue at hand (or your knowledge has been called in to question, and you are answering that challenge). Let's say "out of the blue" you wanted to state that "you know that" -- and you wanted an emphatic version. Is it correct to say the following?

I let you know that I have sent you a letter. Or is there a better way to say this sentence? For example: I inform you that I have sent you a letter.