You have to add tag support to your Pages.
function page_tags() {
register_taxonomy_for_object_type('post_tags','pages'); // adds tag support
add_meta_box('tagsdiv-page_tag','tags','post_tags_meta_box','page','side','low'); // adds the meta box itself
}
add_action('admin_init','page_tags');
You still won’t see tags anywhere. You can move the meta box around using the ‘side’ and ‘low’ parameters. See the link below.
Now look in TwentyEleven’s content-single.php
and find the get_the_tag_list
line. That is the part you want. You need to edit content-page.php
to look like …
<footer class="entry-meta">
<?php echo get_the_tag_list( '', __( ', ', 'twentyeleven' ) ); ?>
<?php edit_post_link( __( 'Edit', 'twentyeleven' ), '<span class="edit-link">', '</span>' ); ?>
</footer><!-- .entry-meta -->
That should do it.
Be aware that editing a default theme is dangerous. It will be overwritten when you update. You should be creating a child theme.
http://codex.wordpress.org/Function_Reference/register_taxonomy_for_object_type