I want a warning message displayed in the comment form when people try to add comments:
"Please write comments in correct grammatical English, otherwise they will not published"
How can I do it?
Here is how you can do it by using hook_form_alter in your own module:
function mymodule_form_alter(&$form, &$form_state, $form_id) {
switch ($form_id) {
case "comment_form":
$form['#prefix'] .= "<div><p>Show some text before the comment form.</p></div>";
break;
}
}