"I do not at all know what I should do."
Translation:Jag vet inte alls vad jag ska göra.
Just a slight one - "that which" means there is something you should do, but you don't know what it is. On the other hand, with "what" you don't know if there's anything you can do either. Typically in practise, though, "what" tends to cover both in normal conversation. :)
So, first, borde is accepted now (7 months after this conversation), but second, whether what you're saying is linguistically true or not this sentence to me would always mean there's some choice to make - something that can or should be done - but I either don't know what the options are or which path to follow. If I don't know whether there's anything at all to be done I would say "I don't know what I can do".
I think there are a lot of chapters without any explanation whatsoever. Adverbs used with present that should be translated with would and an adverb, etc.
The grammatical explanation are too scarce to be able to follow the exercises or understand why there is one way of using it and not another.
You may have to be more clear about that .. ska translates to both will and should .. with will there no obligation. And kommer att is equivalent to ska in the meaning of will or isn't it?
I know I shouldn't take another cookie, but will I or won't I? Jag vet att jag borde inte ta andra kaka, men ska jag eller inte?
The sentence in this lesson seems to imply the speaker either faces a dilemma (possibly ethical) or is just too lame to come up with something to do. So there is an active choice or a perceived lack of options to actively choose from. I guess that's the meaning of will/should that translates to ska.
Jag vet inte vad jag ska göra. I do not know what I will or should do by choice.
Jag vet inte vad jag kommer att göra. I don't know what I'll be doing at some time in the future, därför att det kommer som det kommer.