I'm going to take over responsibilities from a colleague who's leaving. The colleague has told me what he earns and it's like double my salary.
He has got strengths I don't have but on the other hand I have strengths he was lacking.
My performance will be reviewed beginning of next year. So until then I will try to show my best and show which responsibilities I have taken over.
My question is how to make use of that information of my predecessor's salary to raise my own salary after the review? Tell my employer that I know?