Question

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?

Answer 1

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;
  }
}