not even vs not yet

not even

adv
  • Introduces or constitutes a more emphatic negation or exclusion than "not". 

intj
  • Used to express strong disappointment or disapproval. 

not yet

adv
  • Not quite; not exactly. 

  • Not for the moment, though expected later. 

noun
  • A skill that one is learning but has not yet acquired. 

How often have the words not even and not yet occurred in a corpus of books? (source: Google Ngram Viewer )