php wont show up ….

Hello! i got little problem. When i try add this code inside my template:
<?php
if (is_single()) {
echo “<?php the_category(); ?>”;
} else {
echo ‘Something’;
}
?>
it wont show up, BUT it will show up in code section (mouse right click and that way) and the color of the code is pink. Is the code wrong which i have pasted to begin of the post or what might be the problem? Help if needed 🙁 !