use strict;
use Data::Dumper;

my @items = ('this', 'that', 'that', 'those', 'these', 'them', 'thou');

my $bag;
map {$bag->{$_}++} @items;

print Dumper($bag);

__END__

$VAR1 = {
          'these' => 1,
          'those' => 1,
          'thou' => 1,
          'them' => 1,
          'that' => 2,
          'this' => 1
        };