hardship vs pen in

hardship

verb
  • To treat (a person) badly; to subject to hardships. 

noun
  • Difficulty or trouble; hard times. 

  • A burden, a source of difficulty that could impose a barrier. 

pen in

verb
  • To cause to be stuck in a situation; to be forced into a situation by circumstances. 

  • To enclose (animals) in a pen. 

  • To schedule; fix a date for. 

How often have the words hardship and pen in occurred in a corpus of books? (source: Google Ngram Viewer )