get on vs undertake

get on

verb
  • To commence (an action). 

  • To handle, cope or manage (over time); to perform or make progress. 

  • To board or mount (something), especially a vehicle. 

  • To become late. 

  • To have a good relationship; to get along. 

  • To become old. 

  • To progress (with). 

intj
  • Expresses surprise or disbelief. 

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 get on and undertake occurred in a corpus of books? (source: Google Ngram Viewer )