Auto-Enable Threaded/Nested Comments in WordPress

Threaded comments let people reply to each other

In theme or functionality plugin

You can auto-enable nested comments in your theme’s functions.php file or in your functionality plugin. Just use the code below.

function enable_threaded_comments(){
 if (!is_admin()) {
  if (is_singular() AND comments_open() AND (get_option('thread_comments') == 1))
add_action('get_header', 'enable_threaded_comments');

That’s all there is to it. Threaded/nested comments will automatically be enabled, so you won’t have to turn them on in the WordPress Dashboard like you normally would.