Error in wordpress function.php file - php

Question

I am trying to add a particular shortcode to my theme, but i get an error when i paste the below code in my themes function.php. I already tried including once in the function.php but that did not work.
I think the problem is because of the <?php prefix and ?> suffix it has which is prohibited in wordpress fucntion.php. I had removed all <?php and ?> but it still generates an error.
// Add Shortcode
function acardio_big_grid_1() {
<div class="col-md-12 featt big-grid">
<div class="container-fluid no-padding">
<?php
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args = array('post_type' => 'post', 'posts_per_page' => 5, 'paged' => $paged);
$query = new WP_Query($args);
if( $query->have_posts() ) :
while( $query->have_posts() ) : $query->the_post(); ?>
<?php $count++; ?>
<?php if ($count == 1) : ?>
<div class="big-pane col-xs-6">
<div class="the-big-pane image">
<div class="img-responsive"> <?php if ( has_post_thumbnail() ) : ?>
<?php the_post_thumbnail('big-grid-one-image'); ?>
<?php else : ?>
<img src="
<?php if (function_exists('get_option_tree') ) : if (get_option_tree('defualt_fatured_uploader')) : ?>
<?php get_option_tree( 'defualt_fatured_uploader', '', 'true' ); ?>
<?php else : ?>
<?php echo get_template_directory_uri (); ?>/img/nothumb-featured.png
<?php endif; endif; ?>
" />
<?php endif; ?></div>
</div>
<div class="big-pane overlay">
<div class="the-big-pane-content">
<div class="the-cont-cat">
<span class="the-content-cat-bt"> <?php $category = get_the_category(); if ($category)
{ echo wp_kses_post('<a href="' . get_category_link( $category[0]->term_id ) . '" class="tiptipBlog" title="' . sprintf( esc_html__( "View all posts in %s", "acardio" ), $category[0]->name ) . '" ' . '>' . $category[0]->name.'</a> ');} ?></span> <span class="the-content-cat-bt"> <?php taqyeem_get_score(); ?> </span>
</div>
<h1><?php echo wp_trim_words( get_the_title(), 15 ); ?></h1>
<span class="the-content-post-data"><span class="the-auth-post-image-content" style="padding-top: 0px !important;"> <?php echo get_avatar( get_the_author_meta( 'user_email' ), 100 ); ?> </span> By <?php the_author_posts_link(); ?> <span class="the-content-post-date"> <i class="fa fa-clock-o the-content "></i><?php the_time('jS M, Y') ?></span> </span>
</div>
</div>
</div>
<?php elseif ($count == 2) : ?>
<div class="small-pane-holder1 col-xs-6">
<div class="small-pane col-xs-6 one">
<div class="the-small-pane-image">
<?php the_post_thumbnail();?>
</div>
<div class="small-pane-overlay">
<div class="small-pan-content">
<div class="the-cont-cat">
<span class="the-content-cat-bt"> <?php $category = get_the_category(); if ($category)
{ echo wp_kses_post('<a href="' . get_category_link( $category[0]->term_id ) . '" class="tiptipBlog" title="' . sprintf( esc_html__( "View all posts in %s", "acardio" ), $category[0]->name ) . '" ' . '>' . $category[0]->name.'</a> ');} ?></span> <span class="the-content-cat-bt"> <?php taqyeem_get_score(); ?> </span>
</div>
<h1 class="small-pane-title"><?php echo wp_trim_words( get_the_title(), 10 ); ?></h1>
</div>
</div>
</div>
<?php elseif ($count == 3) : ?>
<div class="small-pane col-xs-6 two">
<div class="the-small-pane-image">
<?php the_post_thumbnail();?>
</div>
<div class="small-pane-overlay">
<div class="small-pan-content">
<div class="the-cont-cat">
<span class="the-content-cat-bt"> <?php $category = get_the_category(); if ($category)
{ echo wp_kses_post('<a href="' . get_category_link( $category[0]->term_id ) . '" class="tiptipBlog" title="' . sprintf( esc_html__( "View all posts in %s", "acardio" ), $category[0]->name ) . '" ' . '>' . $category[0]->name.'</a> ');} ?></span> <span class="the-content-cat-bt"> <?php taqyeem_get_score(); ?> </span>
</div>
<h1 class="small-pane-title"><?php echo wp_trim_words( get_the_title(), 10 ); ?></h1>
</div>
</div>
</div>
<?php elseif ($count == 4) : ?>
<div class="small-pane col-xs-6 three">
<div class="the-small-pane-image">
<?php the_post_thumbnail();?>
</div>
<div class="small-pane-overlay">
<div class="small-pan-content">
<div class="the-cont-cat">
<span class="the-content-cat-bt"> <?php $category = get_the_category(); if ($category)
{ echo wp_kses_post('<a href="' . get_category_link( $category[0]->term_id ) . '" class="tiptipBlog" title="' . sprintf( esc_html__( "View all posts in %s", "acardio" ), $category[0]->name ) . '" ' . '>' . $category[0]->name.'</a> ');} ?></span> <span class="the-content-cat-bt"> <?php taqyeem_get_score(); ?> </span>
</div>
<h1 class="small-pane-title"><?php echo wp_trim_words( get_the_title(), 10 ); ?></h1>
</div>
</div>
</div>
<?php elseif ($count == 5) : ?>
<div class="small-pane col-xs-6 four">
<div class="the-small-pane-image">
<?php the_post_thumbnail();?>
</div>
<div class="small-pane-overlay">
<div class="small-pan-content">
<div class="the-cont-cat">
<span class="the-content-cat-bt"> <?php $category = get_the_category(); if ($category)
{ echo wp_kses_post('<a href="' . get_category_link( $category[0]->term_id ) . '" class="tiptipBlog" title="' . sprintf( esc_html__( "View all posts in %s", "acardio" ), $category[0]->name ) . '" ' . '>' . $category[0]->name.'</a> ');} ?></span> <span class="the-content-cat-bt"> <?php taqyeem_get_score(); ?> </span>
</div>
<h1 class="small-pane-title"><?php echo wp_trim_words( get_the_title(), 10 ); ?></h1>
</div>
</div>
</div>
</div>
<?php else : ?>
<?php endif; ?>
<?php endwhile; ?>
<?php endif; ?>
</div>
</div>
}
add_shortcode( 'acardio-big-grid-1', 'acardio_big_grid_1' );

Answer 1

Right near the top you have a syntax error - an issue with your PHP tags. You need a closing php tag before the HTML, and an opening PHP tag after. The top of the code should read like so:
function acardio_big_grid_1() {
?>
<div class="col-md-12 featt big-grid">
<div class="container-fluid no-padding">
<?php
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args = array('post_type' => 'post', 'posts_per_page' => 5, 'paged' => $paged);
You have a similar problem near the end of the code sample, but this time missing a opening php tag:
<?php endwhile; ?>
<?php endif; ?>
</div>
</div>
<?php
}
add_shortcode( 'acardio-big-grid-1', 'acardio_big_grid_1' );
No guarantees that that is all your issues, but that would be one key issue in the code sample you provided.