Question

Change in indirect speech : the teacher said to the boy, " do not shirk work."

Answer 1

THE TEACHER INSTRUCTED THE BOY NOT TO SHIRK WORK.

HERE , SINCE THE TEACHER IS ASKING THE BOY TO ABIDE BY SOMETHING ,THEREFORE , IT IS AN IMPERATIVE SENTENCE, SO THERE IS NO CHANGE OF TENSE IN THE REPORTED SPEECH , ONLY THE NEGATIVE DEGREE ,'NOT ' IS USED BEFORE ..

Answer 2

The teacher said to boy you are requested not to shirk your work.