behave vs undertake

behave

verb
  • To conduct (oneself) well, or in a given way. 

  • To act in a polite or proper way. 

  • To act, conduct oneself in a specific manner; used with an adverbial of manner. 

undertake

verb
  • To take upon oneself; to start, to embark on (a specific task etc.). 

  • To commit oneself (to an obligation, activity etc.). 

  • To pass a slower moving vehicle on the curbside rather than on the side closest to oncoming traffic. 

noun
  • The passing of slower traffic on the curbside rather than on the side closest to oncoming traffic. 

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