You, sir, are a gentleman and a scholar.

This fine example of my stupidity will rank highly among its countless peers.

Just in case someone gets here looking for a working example, here it is:

use v5.14;
use Regexp::Grammars;

my $sentence = "Show me the money";

my $grammar = qr{
    <nocontext:>
    <Sentence>
    <rule: Sentence>    <VerbGroup> <NounGroup>
    <rule: VerbGroup>   <Verb> <VPostfix>?
    <rule: Verb>        <.Word>
    <rule: NounGroup>   <NPrefix>? <Noun>
    <rule: Noun>        <.Word>
    <rule: VPostfix>    me | us | them
    <rule: NPrefix>     a | an | the | some
    <rule: Word>        \w+
}x;


sub parse {
    my $s = shift;
    say "The sentence is: $s";
    if ($s =~ $grammar) {
        use Data::Dumper;
        print Dumper \%/;
    }
    else {
        say "I did not understand you."
    }
}

parse ($sentence);
[download]

The result looks like this:

The sentence is: Show me the money
$VAR1 = {
          'Sentence' => {
                          'NounGroup' => {
                                           'NPrefix' => 'the',
                                           'Noun' => 'money'
                                         },
                          'VerbGroup' => {
                                           'Verb' => 'Show',
                                           'VPostfix' => 'me'
                                         }
                        }
        };
[download]