[Grammar] what or that

[tetedd]

Which is the correct sentence and why?
1/ I don't remember something important that she told me.
2/ I don't remember something important what she told me.
Thanks.

 

[Tdol]

That- now can you see why?

 

[tetedd]

Thanks!
I think it's the place of the relative pronoun "that".

 

[Tdol]

You could say I don't remember what she told me (what = the thing that), but not something important what she told me.

 

[tetedd]

Thanks!

 

[Rover_KE]

There is no need to write a new post to say Thanks,​ tetedd. Your click on the Thank button sufficed. It means that we don't have to open the thread again to read your new post and then find that it doesn't include any new information or an additional question. It saves everybody's time.​