<form role="search" method="get" class="searchform" action="<?php echo home_url( '/' ); ?>">
<div class="searchform-content">
<input type="text" placeholder="Kelimenizi buraya yazın..." name="s" id="s" class="custom-search" />
<input type="submit" value="<?php _e( 'Ara', 'blogotron' )?>" />
</div><!-- .searchform-content -->
</form>

Şunu deneyin

Olmazsa bunu denersiniz

<form role="search" method="get" class="searchform" action="<?php echo home_url( '/' ); ?>">
<div class="searchform-content">
<input type="text" value="<?php _e( 'Kelimenizi buraya yazın..', 'blogotron' )?>" name="s" id="s" class="custom-search" />
<input type="submit" value="<?php _e( 'Ara', 'blogotron' )?>" />
</div><!-- .searchform-content -->
</form>