I am not getting the right answer and i don't know what i am doing wrong

Hi there, Mackenzie Kirkham!

I think maybe you misunderstood what they meant by the interpolated greeting. They weren't looking for a variable named that. What they want is for greeting to say "Hi there, Mackenzie". Without you writing it out. Now in Swift there are two ways of putting together strings. There's concatenation. And there's interpolation. Concatenation is simply using a plus sign. And we'd write that as such:

let word1 = "Hello "
let word2= "world!"
return word1 + word2

This code would return the full string of "Hello world!". That's concatenation.

It's asking for interpolation which is the use of a backslash and parentheses to mark the space where you want to put the value of a variable. Take a look:

// Enter your code below
let name = "Mackenzie"
let greeting = "Hi there, \(name)."

Now greeting is equal to "Hi there, Mackenzie.". If you were to leave off the backslash and parentheses the greeting would be equal to "Hi there, name.". Which, obviously, isn't what you're after.

Hope this helps!