I'm confused about the ~te shimau grammar. Can someone help?

Question

I want to say the sentence, I don't know how to wake up early (which I regret). I thought it would be...

Hayaku okikata ga wakatte shimau.

Now, does that mean, "(regrettably) I DO NOT know how to wake up early", or is it "(regrettably) I DO know how to wake up early"?

Thanks for any help :)

Answer 1

Hayaku okikata ga wakatte shimawanai*

All set.

Plain aff= Shimau, Plain neg= shimawanai

Polite aff= Shimaimasu Polite neg- Shimaimasen

Answer 2

At the moment, you're saying "(regrettably) I DO know how to wake up early." You need to make it negative.