Question

If you had not pitied me, you would have been killed.
Change to compound sentence

Answer 1

By definition, a compund sentence is a one which has a minimum of 2 independent clauses that are joined either by a comma, a semi colon or a conjunction.  

Here the sentence can be written as 'you wouldn't have been killed for you had pitied me' or 'You had pitied me so you wouldn't have been killed.'