piece of work vs task

piece of work

noun
  • A product or manufactured article, especially an item of art or craft. 

  • A person who has a strong and unusual personality, especially one with seriously unpleasant character flaws (e.g. a nasty piece of work). (This sense came about due to Hamlet’s soliloquy (see sense 1 above)). 

task

noun
  • A piece of work done as part of one’s duties. 

  • Any piece of work done. 

  • A difficult or tedious undertaking. 

  • A process or execution of a program. 

  • An objective. 

verb
  • To charge, as with a fault. 

  • To assign a task to, or impose a task on. 

  • To oppress with severe or excessive burdens; to tax 

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