1 a. 'Knows not' means "does not know", and 'of' means "something (anything) of" or "regarding". b. It could also be that 'not' is being used as an old form of 'nothing', 'naught'. They come to mean the same thing, and in a sense one doesn't need to decide which is correct..
2. "in the above sentence", "in the sentence above" or sometimes (but not very useful here) "above in t
I had a look but couldn't find a reference to the suggested 1b usage as a form of naught/nothing in older English, perhaps someone else can find one though. d