Interesting module (it's pointers like this that keep me hanging around the monastery). Tiny quibble: you need curlies to have a 0-based index.

print pluralize "There (is|are) (no|one|%d) slice(s) of pizza left.", 
+0;
There are 0 slices of pizza left.

print pluralize "There (is|are) (no|one|%d) slice(s) of pizza left.", 
+1
There is no slice of pizza left.

print pluralize "There (is|are) {no|one|%d} slice(s) of pizza left.", 
+0;
There are no slices of pizza left.
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