use strict;
use warnings;
use Data::Dumper;
use XML::LibXML;
use Lingua::EN::Tagger qw(add_tags);

my $text = <<'EOT';
The set of POS tags used here is a modified version of the
Penn Treebank tagset. Tags with non-letter characters have been 
redefined to work better in our data structures.
EOT

my $tagger = Lingua::EN::Tagger->new;
my $tagged = $tagger->add_tags($text);

my $tree = XML::LibXML->load_xml(string => "<doc>$tagged</doc>");

my @tags = qw(CC DET NN NNP RB VBZ); # add the rest
my %count;

for my $tag (@tags) {
	my $lctag = lc($tag); # lowercase tag name
	my @nodes = $tree->findnodes("//$lctag");
	$count{$tag} = scalar @nodes;
}
print Dumper(\%count);
for my $tag (sort keys %count) {
	print "$tag:\t$count{$tag}\n";
}