my $filename = '/path/to/file.csv';
open (my $fh, '>', $filename) or die "Could not open $filename, $!";
my @headers = qw(
	DET
	IN
	JJ
	NN
	VBD
);
print $fh join(',',@headers) . "\n";

# then, for each of your phrases
print $fh join(',', map($tags{$_} || 0, @headers) ) . "\n";

close $fh;

##</code><code>##

use Tie::Array::CSV;
my $filename = '/path/to/file.csv';
tie my @file, 'Tie::Array::CSV', $filename;

# (this bit has been fixed - see comment below)
# for each of your phrases
my @row = map { $tags{$_} || 0 } @headers;
push(@file,\@row);

untie @file;