If and copy in spreadsheet

I have Column A with names in it. Column D contains values fro 0 to 100.
Suppose in row 25 I have John in A25 and zero (0) in D25 I want I25 to have a copy of A25.
Is there some way to do this?

What is the rule for I25 cell? I mean, you want to “mirror” A25 in I25 because A25 value is “Jonh” or because D25 is 0, or because both conditions are true. Or something else to be considered?

If D25 is zero then I want I25 to mirror A25

Well the example in help is different to what I get if I insert a function.
Like this:
Help says IF(Test; ThenValue; OtherwiseValue)
Creating a function shows this:
IF(Test, ThenValue, OtherwiseValue)
i.e comma not semi-colon
The function one works BUT if I later delete the zero in D25 it still shows A25 in I25 unless I put a different value, even a space character in D25 so it’s still not what I want.
Any idea how I can fix this?

This is not an answer to the original question, so please post it as a comment to your question above. And please also add info, how your actual formula in I25 does look like. Should be something like =IF(D25=0,A25,0), although I do not know what OtherwiseValue you want to have in case D25 is not 0. Empty cell has value (not text string) of 0, so deleting (emptying) cell contents leaves it’s value 0, that is why test D25=0 still returns True.