IF ELSE in Excel for Mac 2016

I am trying to make the third argument in this function so that the "value if false" is a blank cell. I have tried every which variation of how to leave a blank cell if the first argument is not true as well as researched this site and google. It just does not work for me, perhaps because I'm using Mac Excel 2016? And advice on the formula here is much appreciated: =IF(FIND("quality",A80),SUBSTITUTE(A80,A80,"A quality life demands quality questions")," ")

The screen shot below shows how I entered the formula and got #VALUE! errors for cells not TRUE to first argument.

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