One Particular Class To Permalink

I’ve a WordPress website that has been up and operating for some years utilizing the customized permalink construction of: /%postname%/

That is advantageous, besides I need to launch a particular part wherein posts go in a listing, for instance: /particular/%postname%/

What is the correct option to go about this? A customized put up kind would work, however actually the template and put up kind is simply an article.

I feel there’s a approach to do that with a rewrite, one thing like

perform append_query_string( $url, $put up, $leavename=false ) {
    if ( $category->term_id == 'particular' ) {
        $url = add_query_arg( 'particular', $url );
    }
    return $url;
}
add_filter( 'post_link', 'append_query_string', 10, 3 ); 

however I am simply beginning and will use some pointers. Thanks!