The prefix notation may be throwing you off or perhaps you have mistaken the function `bottles` for the string "bottles".

The code `(bottles i)` in the loop is calling the function `bottles` (defined at the top) with the argument `i`. The value of `(bottles 99)` is `(string 99 " bottles")` which evaluates to "99 bottles", as expected.

You aren't understanding Janet. (bottles i) invokes the bottles function with parameter i, so the lyric is "99 bottles of beer on the wall".