No English dictionary has been able to explain the difference between the two words 'complete' and 'finished' in a way that's so easy to understand:…………
Some people say there is no difference between COMPLETE & FINISHED but there is:
When you marry the right one, you are COMPLETE....
And when you marry the wrong one, you are FINISHED.....
And when the right one catches you with the wrong one, you are...COMPLETELY FINISHED !!! :-)
To my mind,if the task has been completed,it means, that you have done it up to the end,it have been checked and have got any result-positive or negative-no matter,but saying"The task has been finished", you suppose to announce, that you have just done it without any check.