when you tried "$people{me}[2] = @sentences;" you were assigning the number of elements that @sentences has to $people{KEY}[2], noticing that you have updated the @sentences with new values for the other hash key, I did not pass it by reference either, instead I did the assignment as "$people{KEY}[2]= "@sentences""...

The concept is that the hash keys in this case are array references and hence they need to be treated accordingly, "@{$people{$person}}", this is visible by using the Data::Dumper module ...Here is my take at your post

#!/usr/local/bin/perl
use strict;
use warnings;

my %people;
my @sentences = ("here i am","i am me");
$people{me}[0] = 0;
$people{me}[1] = "1985";
$people{me}[2] = "@sentences"; #interpolating...

@sentences = ("there she is");
$people{friend}[0] = 1;
$people{friend}[1] = "1984";
$people{friend}[2] = "@sentences";




foreach my $person (keys %people){     #each key references an anonymo
+us array.
        my $rowId = $people{$person}->[0];
        my $DOB =   $people{$person}->[1];
        my $sentence = $people{$person}->[2];
        addDOBToDatabase($rowId, $DOB);
        addSentenceToDatabase($rowId, $sentence);
        }
        
sub addDOBToDatabase{
    my @args = @_;
    print "ID:$args[0], DOB:$args[1]\n";
    }
    
sub addSentenceToDatabase{
    my @args = @_;
    print "ID::$args[0], Sentence: $args[1]\n";
    }

#Viewing data structures can help make decisions on the looping strate
+gy...

use Data::Dumper;
print "\n\UViewing the Data Structure through Data::Dumper:\E\n";
print Dumper(\%people);
[download]

Finally, here is a bunch of links that were very useful to me at clarifying the concept of references, perlref, References quick reference, Referencing in advanced data structures, perldsc and I don't understand hash references...

Updated:Added links