I am pretty new in WordPress development and I am trying to implement this custom theme that handle the so called featured posts: http://lnx.asper-eritrea.com/

As you can see in the posts area of the homepage I have the Articoli in evidenza sub area that contains my featured posts and under it the Ultimi Articoli subarea that contains the latest posts.

To implment this I use the posts tag and in the futured posts area I show the posts having the tag=featured condition.

So this is my code:

<section id="blog-posts">

<header class="header-sezione">
        <h2>Articoli in evidenza</h2>
</header>

<?php query_posts('tag=featured');?>
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
  <div id="featured-posts">

    <h1><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></h1>
      <div class="meta">
Scritto da <span class="author"><?php the_author_link(); ?></span> &nbsp;//&nbsp;  <?php the_category(', ') ?>  &nbsp;//&nbsp;  <?php comments_popup_link('Nessun Commento', '1 Commento ', '% Commenti'); ?> 
      </div>
      <div class="featured-details"><?php the_excerpt()?>
      <?php $featured_img = get_post_meta($post->ID, 'featured_img', $single = true); ?>
      <a href="<?php the_permalink(); ?>"><img src="<?php echo $featured_img ?>" alt="<?php the_title(); ?>" /></a>
      </div>
    </div>

<?php endwhile; ?>
<?php else : ?>
<?php endif; ?>



    <header class="header-sezione">
        <h2>Ultimi Articoli</h2>
    </header>

    <?php
    if (have_posts()) :
        // Start the Loop.
        while (have_posts()) : the_post();

            /*
             * Include the post format-specific template for the content. If you want to
             * use this in a child theme, then include a file called called content-___.php
             * (where ___ is the post format) and that will be used instead.
             */
            get_template_part('content', get_post_format());

        endwhile;
    else :
        // If no content, include the "No posts found" template.
        get_template_part('content', 'none');

    endif;
    ?>

</section>

As you can see first I show the posts having a tag featured by the use of query-posts() function:

<?php query_posts('tag=featured');?>

Now my problem is that if a post have the featured tag I don't want that it is shown in the latest post area (at this time it is shown). So I tried to use this code:

<header class="header-sezione">
    <h2>Ultimi Articoli NOT FEATURED</h2>
</header>

<?php query_posts('tag != featured');?>

<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
  <div id="featured-posts">

    <h1><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></h1>
      <div class="meta">
Scritto da <span class="author"><?php the_author_link(); ?></span> &nbsp;//&nbsp;  <?php the_category(', ') ?>  &nbsp;//&nbsp;  <?php comments_popup_link('Nessun Commento', '1 Commento ', '% Commenti'); ?> 
      </div>
      <div class="featured-details"><?php the_excerpt()?>
      <?php $featured_img = get_post_meta($post->ID, 'featured_img', $single = true); ?>
      <a href="<?php the_permalink(); ?>"><img src="<?php echo $featured_img ?>" alt="<?php the_title(); ?>" /></a>
      </div>
    </div>

<?php endwhile; ?>
<?php else : ?>
<?php endif; ?>

But don't work and the featured post still shown in the homepage. As you can se I tried so specify that, to be shown, a post can't have the featured tag:

<?php query_posts('tag != featured');?>

Why don't work? What am I missing? Can you help me to fix this issue?

Tnx

To return posts that do not contain a particular tag, you should use pass the ID of the term into the tag__not_in argument.

// get the term using the slug and the tag taxonomy
$term = get_term_by( 'slug', 'featured', 'post_tag' );
// pass the term_id to tag__not_in
query_posts( array( 'tag__not_in' => array ( $term->term_id ) );

is_front_page()

You should try <?php is_front_page(); ?> or vice versa.

http://codex.wordpress.org/Function_Reference/is_front_page

<?php if (is_front_page()) { ?>
    <!-- Do something -->
<?php } else { ?>
    <!-- Add else only if you need it! -->
<?php } ?>