[Grammar] I didn't know vs I don't know

[LiuJing]

--Do you know Slovenia is the smallest nation in the current FIFA World Cup Tournament?

Answer 1--No, I don't.
Answer 2--Really? I didn't know that.

For the second answer, can ' I don't know that ' be applied in place of 'I didn't know that' ? Thank you.

 

[tedtmc]

--Do you know Slovenia is the smallest nation in the current FIFA World Cup Tournament?

Answer 1--No, I don't.
Answer 2--Really? I didn't know that.

For the second answer, can ' I don't know that ' be applied in place of 'I didn't know that' ? Thank you.

No. I didn't know that (until now that I have been told).

not a teacher

 

[Heterological]

tedtmc has it right: "I didn't know" or "I didn't know that" is correct, because now you do know, since the person just told you!

 

[Barb_D]

I find it a bit more natural to use "Did you know..." when you are giving a fact (you're providing the knowledge).

I would use "Do you know..." when you are asking a genuine question. (Do you know what time the bus stops here? Do you know what time Mom said she was getting home?)

 

[emsr2d2]

I find it a bit more natural to use "Did you know..." when you are giving a fact (you're providing the knowledge).

I would use "Do you know..." when you are asking a genuine question. (Do you know what time the bus stops here? Do you know what time Mom said she was getting home?)

I agree. With questions about general knowledge, they tend to start "Did you know...?" I take this to mean "Did you already know ... or is this new information for you?"

 

[LiuJing]

I find it a bit more natural to use "Did you know..." when you are giving a fact (you're providing the knowledge).

I would use "Do you know..." when you are asking a genuine question. (Do you know what time the bus stops here? Do you know what time Mom said she was getting home?)

Your notion of this is very informative. Thank you.
Then, how do we reply to such an 'ingenuine' question?

I can quite understand the negative answer to that, but is the positive reply "Yes, I did'' ? Thank you.

 

[Barb_D]

If someone comes to me with a new piece of news, or even an old, old fact, she can start with "Did you know..." and then tell me.

If I did know, I could say "I know! Isn't that amazing!" or "I just heard!" or "Yes, I learned it in a great college course I took and found it fascinating!" (or "Yeah, but who cares?" although that would be rude).


If I didn't, I could say "You're kidding!" (an expected response when there is "big news" to tell) or "Really? That's amazing!" or a milder "Huh. No, I didn't, but thanks for letting me know" (be careful, the last could sound sarcastic).

 

[euncu]

***neither a teacher nor a native-speaker***

One can be sarcastic by using "I didn't know that" but not by "I don't know that".