The input captured into $verb will probably end in a newline. You should use chomp to rid your string of that unwanted clutter.
Your split statement splits into void context (the return value is not captured), and the parameters are wrong; you certainly don't want to treat $verb as a pattern.
Your for statement increments $i before entering the loop, and never again. The $i++ should appear after the last semicolon, not before the first one.
Your second print statement includes $verb-3, which will result in -3 being printed, and if warnings are enabled, a warning being generated, because $verb will probably not contain anything resembling a number, so Perl will treat it as a zero in numeric context.
You are using @pronouns_ending to hold two types of data in a confusing way. Better to use an array of array-refs, or some data structure that better reflects the relationships of the data that are currently only represented by partitioning the array.
You lack a final }, preventing compilation.
You aren't using strict and warnings -- tools that will aid in preventing or discovering other common pitfalls.