However and how.

[lindadanca]

Hello,

I would like to ask my first question for today. :)

How fast can you type? (It is correct)

But,

1) Tell me. How could you drive this car so fast?

2) Actually, I can't know about how you can drive this car fast.

Are they correct? Can we use 'adjective' and 'adverb' apart from 'how'?

Thanks

[5jj]

How fast can you type?

1a) Tell me. How could you drive this car so fast?
1b) Tell me how you could drive this car so fast.

#1a and 1b are both acceptable. #1c is also acceptable though it has a different meaning:

1c) Tell me how fast you could drive this car.

2) Actually, I can't know about how you can drive this car fast.

I am not sure what you mean here. These are possiblities:
I don't know how fast you can drive this car.
I don't know how you can drive this car so fast.
I don't know anything about driving this car fast.