effort vs struggle

effort

noun
  • A force acting on a body in the direction of its motion. 

  • An endeavor. 

  • The work involved in performing an activity; exertion. 

verb
  • To make an effort. 

struggle

noun
  • A contortion of the body in an attempt to escape or to perform a difficult task. 

  • Strife, contention, great effort. 

verb
  • To strive, to labour in difficulty, to fight (for or against), to contend. 

  • To strive, or to make efforts, with a twisting, or with contortions of the body. 

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