I don't know how to concatenate echo "<li>$contacts[0]['name'] . " : " . $contacts[0]['email']</li>\n";

<?php
//edit this array
$contacts[] = [
  'name' => 'Alena Holligan', 
  'email' => 'alena.holligan@teamtreehouse.com',
];
$contacts[] = [
  'name' => 'Dave McFarland', 
  'email' => 'dave.mcfarland@teamtreehouse.com',
];
$contacts[] = [
  'name' => 'Treasure Porth', 
  'email' => 'treasure.porth@teamtreehouse.com',
];
$contacts[] = [
  'name' => 'Andrew Chalkley', 
  'email' => 'andrew.chalkley@teamtreehouse.com',
];

echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>$contacts[0]['name']" . " : " . "$contacts[0]['email']</li>\n";
echo "<li>Dave McFarland : dave.mcfarland@teamtreehouse.com</li>\n";
echo "<li>Treasure Porth : treasure.porth@teamtreehouse.com</li>\n";
echo "<li>Andrew Chalkley : andrew.chalkley@teamtreehouse.com</li>\n";
echo "</ul>\n";