for keeps vs never

for keeps

prep
  • With an agreement or intention to retain what one gains or receives. 

  • Permanently, so that one can keep something indefinitely. 

  • With a strong competitive resolve to win or succeed, as in sports or business. 

never

intj
  • A statement of defiance 

adv
  • Negative particle (used to negate verbs in the simple past tense; also used absolutely). 

  • At no time; on no occasion; in no circumstance. 

  • Not at any other time; not on any other occasion; not previously. 

How often have the words for keeps and never occurred in a corpus of books? (source: Google Ngram Viewer )