Unless otherwise indicated, the code snippets you see below should be placed into your theme’s functions.php file.
Here is the code to modify the author says text on your site:
<?php
//* Do NOT include the opening php tag shown above. Copy the code shown below.
//* Modify the author says text in comments
add_filter( 'comment_author_says_text', 'sp_comment_author_says_text' );
function sp_comment_author_says_text() {
return 'author says';
}