**Context** First of all I known it mentioned before. But I'm not sure which is correct. I've been learning about the Past simple and Past perfect and if I've understood correctly, Well, in high level: **Past Simple** - Occur in the past (in specific time) and finished. **Past perfect** - Occur in the past, certainly continues to the present, and maybe continue in the future. 1) This is correct? **--The main Question--** > have you known that Harald has a very bad disease? So, [Here][1] someone explain that, **"Did you see this?"** is for case that happened in the past but it finished/passed (you can't see it anymore). However, use **"Have you seen this.."** if you missed that, you still can see that. is Correct? So I thought why not, if I ask someone: **have you known that she passed her driving test?** (Did you hear that she passed the driving test? if not, now you can still know about this, related to above explanation) Well, [Here][2] I found that example about Harald, and they commented that you never can say "**Have you known...**" only did you know, but they didn't explain, why is it grammatically incorrect? 2) Actually, I want to understand what is correct, and why in context to past simple and present perfect. and when I can use both of them correct in questions. Thanks All !!! [1]: https://english.stackexchange.com/a/4860 [2]: https://forum.wordreference.com/threads/did-you-know-have-you-known-be.2052222/