<?php

$config = [
    'components' => [
        'urlManager' => [
            'enablePrettyUrl' => true,
            'showScriptName' => false,
            'rules' => [
                '<controller:\w+>/<action:\w+>' => '<controller>/<action>',
            ],
        ]
    ],
];

class SiteController extends Controller {
	
	public function actionSay($message = 'Привет')
	{
	    return $this->render('say', ['message' => $message]);
	}
	
}

//views/site
<?php
use yii\helpers\Html;
?>
<?= Html::encode($message) ?>
