<?php if(Yii::$app->controller->action->id == 'update' && $special_item) : ?>

<?= $form->field($special_item, 'item_id')->dropDownList(ArrayHelper::map($items, 'id', Yii::$app->language == 'en' ? 'english_name' : 'arabic_name'),[
    'prompt' => Yii::t('app', 'Select Main Category'),
]) ?>

<?php endif; ?>